Research in Progress 2004 - 2005

Department of Materials

Table of Contents

Foreword from the Head of Department ...... iii Members of Department...... iv Profiles of Academic Staff...... ix

A. Structure and Mechanical Properties of Metals ...... 1 I. Mechanical Properties of Strong Solids, Metals and Alloys...... 1 II. Intermetallics ...... 3

B. Non-Metallic Materials...... 4 I. Ceramics and Composites...... 4 II. Biomedical Materials...... 5 III. Polymers...... 7 IV. Photovoltaic Materials ...... 10

C. Electronic Materials and Devices...... 11 I. Superconducting Materials ...... 11 II. Semiconductor Materials...... 12 III. Magnetic Materials...... 13 IV. Quantum Information Processing ...... 14

D. Processing ...... 17

E. Phase Transformations, Surfaces and Interfaces...... 21 I. Phase Transformations...... 21 II. Oxidation and Corrosion ...... 22 III. Surface Reactions and Catalysis...... 22

F. Characterisation ...... 23 I. Scanning Tunnelling and Atomic Force Microscopy ...... 23 II. Field-Ion Microscopy and Atom Probe Microanalysis...... 25 III. Electron Diffraction and Transmission Microscopy, Scanning Electron Microscopy, X-Ray Microscopy and Microanalysis...... 26 IV. Radiation Damage...... 32

G. Modelling and Simulation...... 33

H. Materials Science Based Archaeology...... 36

Recent Publications ...... 38

i Research in Progress 2004-2005 Department of Materials

University of Oxford

Department of Materials Keble Road Triangle

Department of Materials Engineering / Physics Elevated Walkway

Department of Materials N 1 - HumeRothery Building 2 - Holder Building 3 - Wolfson Building 4 - 21 Banbury Road 5 - 12/13 Parks Road 6 - Nuclear Physics Basement

Pear Tree Visitor’s Park and Parking Ride bus-stop

City Centre

Department of Materials Begbroke Business and Science Park Unversity of Oxford Parks Road Oxford OX1 3PH

8a Phone : +44-1865-273700 9 Hirsch Fax: +44-1865-273789 8 10 Building [email protected] Science Park http://www.materials.ox.ac.uk 4 Also 3

2 Begbroke Science Park Sandy Lane, Yarnton Oxford OX5 1PF Entrance

Phone : +44-1865-283700 Fax: +44-1865-2848790 [email protected] http://www.begbroke.ox.ac.uk

Foreword from the Head of Department Welcome to the Department of Materials at Oxford University. Our objectives are to produce world class graduate materials scientists and engineers, and to conduct world class research into the manufacture, structure, properties and applications of materials, for the benefit of the UK and world community. We were awarded the highest “five star star” grading for research in the government's most recent assessment exercise, and we consistently top the overall performance league tables for UK Materials Departments. Major achievements in recent years include: 1. Five elections to Fellowships of the Royal Society (David Cockayne, John Pethica, Brian Eyre, John Hunt and Adrian Sutton) and two to the Royal Academy of Engineering (Richard Brook and Brian Cantor); 2. Awards and honours to members of the Department, including the Royal Society Armourers and Brasiers Award (David Pettifor, John Hunt), the Royal Society Hughes Medal and the IofP/SFP Holweck Medal and Prize (John Pethica), the Institute of Materials Platinum Medal (John Martin, Brian Cantor), Acta Materialia Gold Medal (George Smith), the Beilby Medal and Prize (Alfred Cerezo), the Pfeil Award (Richard Todd), Metrology for World Class Manufacturing Awards (Andrew Briggs, Oleg Kolosov, John Hunt), National Award for Innovative Measurement (Alfred Cerezo, Terence Godfrey and George Smith) and election to the US National Academy of Engineering and award of the Heyn-Denkmunze prize of the German Materials Society (Sir Peter Hirsch). Brian Cantor was appointed Vice-Chancellor of the University of York, Richard Brook received a knighthood, and was appointed Director of the Leverhulme Trust, Andrew Briggs was appointed as the Director of a new Quantum Information Processing IRC, John Hutchison was elected President of the Royal Microscopical Society and David Cockayne was elected President of the International Federation of Societies of Microscopy (2003-6). 3. Appointment of Andrew Briggs to the Professorship of Nanomaterials and Patrick Grant to the Cookson Professorship of Materials. 4. Four promotions to personal professorships (Adrian Sutton, Amanda Petford-Long, Alfred Cerezo and Chris Grovenor) and four promotions to readerships (John Hutchison, Mike Jenkins, Steve Roberts and John Sykes); 5. Over £8m from the Joint Infrastructure Fund, to purchase cutting edge equipment for atomically engineered, nanoscale materials processing and analysis 6. The launch of the new £22m Begbroke site, which greatly expands the Department's space, and sets up a unique combination of industry-linked materials research and spin-out science park; 7. The establishment of a Faraday Partnership in aerospace and automotive materials; and 8. The designation of the Department as the main hub for the new £9.2m IRC in Quantum Information Processing. This follows the award of a £3.4m DTI Foresight Link grant for research on nanoelectronics and quantum computation. The Department was founded by Professor Hume-Rothery in 1956. At present, it consists of 22 academics, 20 senior researchers, 51 postdoctoral researchers, 38 technicians and administrative staff, 77 academic visitors, 103 research students and 94 undergraduates. The Department is part of an integrated Division of Mathematical and Physical Sciences at Oxford, which includes physics, chemistry computing and engineering departments, providing an ideal environment for interdisciplinary teaching and research. Fundamental developments in the physics and chemistry of materials can take place directly alongside applications in manufacturing processes and engineering design. This booklet describes the full range of our current research programmes within the Department. The Department of Materials at Oxford provides a vibrant and stimulating environment, and acts as an academic meeting point for materials scientists and engineers from all over the world. We are always pleased to discuss our research projects in more detail. We actively seek applications from new undergraduates, research students and research fellows, and we are keen to investigate further opportunities for collaboration and scientific exchanges. Please do not hesitate to contact us by letter, phone, fax or e-mail. Professor G.D.W. Smith FRS October 2004

iii Research in Progress 2004-2005 Members of Department Professors Professor G.D.W. Smith, FRS Head of Department

Professor D.G. Pettifor, FRS Isaac Wolfson Professor of Metallurgy Director of the Materials Modelling Laboratory

Professor P.S. Grant Cookson Professor of Materials Processing Director of Oxford Centre for Advanced Materials and Composites Director of Faraday Partnership in Aerospace and Automotive Materials Professor D.J.H. Cockayne, FRS Professor in Physical Examination of Materials

Professor J.M. Titchmarsh* The Royal Academy of Engineering/ AEAT / INSS Research Professor in Microanalysis and Structural Integrity

Professor G.A.D. Briggs Professor of Nanomaterials Quantum Information Processing Interdisciplinary Research Collaboration Professor C.R.M. Grovenor Deputy Head of Department Professor A. Cerezo Professor of Materials Professor A.K. Petford-Long Professor of Materials Professor A.P. Sutton*, FRS Professor of Materials Science Professor J.B. Pethica, FRS Visiting Professor Professor C.R. Whitehouse Visiting Professor Professor J.V. Wood FREng Visiting Professor Professor Sir Richard Brook, OBE FREng Emeritus Professor Professor Sir Peter Hirsch, FRS Emeritus Professor Professor J.D. Hunt, FRS Emeritus Professor Professor M.J. Whelan, FRS Emeritus Professor Readers Dr. M.L. Jenkins Director of Electron Microscopy Facilities Dr. J.L. Hutchison Reader in Materials Dr. S.G. Roberts Reader in Materials Dr. J.M. Sykes Reader in Materials Lecturers Dr. H.E. Assender Lecturer in Materials Dr. D.G. Bucknall* Lecturer in Materials Dr. J.T. Czernuszka Lecturer in Materials Dr. P.J. Northover Lecturer in Materials Dr. K.A.Q. O'Reilly Lecturer in Materials Dr. J.M. Smith Lecturer in Materials Dr. R.I. Todd Lecturer in Materials Dr. P.R. Wilshaw Lecturer in Materials

* due to leave at the end of 2004 iv Members of Department

Administration Dr. R.M. Plummer Administrator Ms. R.A. Meyrick Deputy Administrator (Finance) Dr. L.J.F. Jones Deputy Administrator (Academic) Dr. A.O. Taylor Director of Studies Senior Research Fellows Dr. R. Ball Wolfson Industrial Fellow Dr. A.I. Kirkland Leverhulme Senior Research Fellow Prof. A. Balazs OCAMAC Senior Fellow (Pittsburgh) Dr. J.W. Martin OCAMAC Senior Fellow Dr. S.C. Benjamin Royal Society Research Fellow Dr. Duc Nguyen-Manh OCAMAC Industrial Fellow (UKAEA) Dr. R. Bhatti Senior Visiting Fellow (QinetiQ) Dr. C. Nörenberg RS Dorothy Hodgkin Fellow Dr. G.R. Booker OCAMAC Senior Fellow Dr. J. Sloan Royal Society Research Fellow Dr. M.R. Castell Royal Society Research Fellow Dr. I.C. Stone Senior Research Fellow Dr. S.L. Dudarev OCAMAC Industrial Fellow (UKAEA) Dr. G. Taylor Senior Research Fellow Dr. R. Falster OCAMAC Industrial Fellow (MEMC) Dr. D. Vesely OCAMAC Senior Fellow Dr. N. Grobert RS Dorothy Hodgkin Fellow Dr. P.D. Warren OCAMAC Industrial Fellow (Pilkington) Dr. B. Gilmore Senior Visiting Fellow Dr. A.J. Wilkinson Senior Departmental Research Lecturer Dr. D. Imeson Senior Visiting Fellow (DSTL) Research Fellows Dr. V. Burlakov Dr. Y. Huang Dr. S. Lozano-Perez Dr. Z. Shi Dr. A.M. Cock Dr. T.S. Hudson Dr. C.D. Marsh Dr. F. Silly Dr. A. Crossley Dr. C. Johnston Dr. D.R. Mason Dr. H. Smith Mr. F. Cullen Dr. M. Kilburn Dr. J. Mercer-Lynch Mrs. S.C. Speller Dr. M. Döblinger Dr. K.R. Kirov Dr. R.R. Meyer Dr. T. Starke Mr. R.C. Doole Dr. K. Kohary Dr. J. Mi Dr. M. Tanaka Dr. R. Drautz Dr. A. Kohn Mr. A. Nazir Dr. J. Topping Dr. A. Dupuis Dr. C Lang Dr. I.G. Palmer Dr. P.J. Warren Dr. C. Dwyer Dr. L Lauro-Taroni Mr. M. Porcu Dr. S.J. Wilkins Mr. T.J. Godfrey Dr. S.M. Lee Dr. K. Porfyrakis Dr. G.B. Winkelman Dr. B.M. Henry Dr. J. Leopoldes Mr. C.J. Salter Dr. J. Yang Dr. C.J.D. Hetherington Dr. C. Liu Dr. S. Senkader Dr. S.C. Hogg Dr. B. Lovett Dr. G. Sha D.Phil and MSc. Research Students Abraham, M.H. (self-supporting) Castro Diaz, L. (Regenesys / Linacre) Ahmed, S. (CASE: Corus) Chadd, G. (Crown Cork & Seal) Alpass, C. (EPSRC DTA) Chen, X. (self-supporting) Austwick, M.R. (EPSRC) Chen, Y. (self-supporting and Linacre) Bagot, P. (EPSRC) Clarke, E. (EPSRC CASE: Corus) Barkhouse, A (Rhodes Scholarship) Colley, L. (EPSRC) Bernardo, G. (self-supporting) Dancer, C. (EPSRC DTA) Briceno-Gomez, M. (Qinetiq) Dark, C.J. (EPSRC DTA) Britz, D. (EPSRC Foresight Link) Davidson, I. (CASE: Alcoa Extrusions) Bromwich, T. (EPSRC DTA) Davin, L. (EPSRC) Brown, G. (CASE: Colebrand Ltd.) Deak, D. (EPSRC) Campbell, P.J.D. (CASE: BNFL) DeMorais, A. (Nordiko Ltd) Carter, R. (EPSRC) Di Maio, D. (Hardide)

v Research in Progress 2004-2005

Doherty, M.J. (EPSRC) Pilcher-Clayton, A. (UKAEA/EPSRC) Eggeman, A. (EPSRC DTA + CASE: Johnson Matthey) Pinitsoontorn, S. (Thai Gov.) Fraser. K. (EPSRC DTA) Porcu, M. (EPSRC DTA / EU) Galano, M. (EU/Korea/Clarendon/ORS) Ramanujan, C.S. Giannattasio, A. (MEMC Ltd.) Russell, B. (EPSRC DTA) Gotora, D. (Rhodes) Russell-Stevens, M.J. (EPSRC) Grennan-Heaven, N. (CASE: Oxford Nanoscience) Rust, M. (NSF/Clarendon/ORS) Gunlycke, D. (EPSRC Foresight Link) Saran, M. (Perdana Exchange Programme) Haigh, S. (EPSRC DTA) Saunders, S. (CASE: National Physical Laboratory) Hinchliffe, C. (CASE: Rolls-Royce) Scipioni, R. (Self / EPSRC Foresight Link) Howells, D. (CASE: Dupont) Shapiro, I. (EPSRC DTA) Islam, P. (Faraday CASE: Merck) Shinotsuka, K. (self-supporting) Ito, F. Smart, K. (EPSRC) Jones, M. (EPSRC) Srimanosaowapak, S. (Thai Gov.) Joseph, T. (CASE: UKAEA) Stowe, D.J. (EPSRC) Kawata, K. (Toppan Printing Co.) Taylor, R.N. (CASE: Nanox) Kirk, D. (EPSRC) Thomas, G. (CASE: UKAEA) King, O. (EPSRC) Todorovic, M. (Scatchered Scholarship) Korsah, M. (EPSRC) Tse, K-Y. (QIPIRC DTA) Kumar, A. (EPSRC) Tyrrell, E. (EPSRC DTA) Lambourne, A. (Department) Vlandas, A. (EPSRC, St Cross College) Lang, C. (EPSRC) Wahl, D. (EPSRC) Langham, C. (Motorola) Wain, N. (EPSRC) Limpichaipanit, A. (Thai Gov.) Waller, J. (EPSRC) Leigh, D. (EPSRC Foresight Link) Walpole, A. (EPSRC DTA) Marsh, H. (EPSRC DTA) Wang, C. (EPSRC) Martin, C. (EPSRC) Wang, H. (Clarendon/ORS) Mathieson, D. (OPSYS) Waring, M. (EPSRC DTA) Morgan, D.L. (EPSRC) Whiteley, R.M. (EPSRC) Morley, A. (EPSRC DTA) Whyte, E. (CASE:Corus) Morley, G. (EPSRC Foresight Link) Womersley, H. (EPSRC) Morton, J. (EPSRC DTA / NEDO Xie, Z. (Clarendon /ORS) Murphy, J. (EPSRC) Xu, J. (self-supporting) Newell, D. (CASE: Oxford Applied Research) Xu, Q. (Dorothy Hodgkin) Nicholls, R. (EPSRC DTA, St Catherine’s Scholarship) Zhang, J. (Clarendon, ORS, Queens College) Nzula, M. (visiting student, Sainsbury Scholarship) Zhou, Dr Z. (UKAEA) Okayasu, T. (Oji Paper Co.) Zhu, C. (Clarendon) Pak, S.J. (Doorae Research Institute) Zhu, M. (K.C.Wong / ORS) Park, S-B. (self-supporting) (Please note that student lists are correct at the time of going to press.) Part II Students (4th Year Undergraduates) Materials Science Materials, Economics and Engineering and Science Forrest, D. Robinson, J. Management of Materials Armstrong, D. Jackson, V. Chow, H. Faure, J. Lui, A. Wilson, C. Luoma, A. Davies, R. Karney, G. Duggan, A. Parry, S. Pygall B. Howells, M. Williams, E. Hyslop, D. Thomas, L. Walsh, J Holme, P. Secretarial and Technical Support Mr. P. Abbott Mrs. K. Davies Mr. T.S. Knibbs Mr. I. Sutton Mr. S. Aldworth Mr. R. East Mr. K. Leatherby Ms. D.M. Taylor ( Mr. A.B. Bailey) Mr. B.J. Fellows Mr. S. Lett Mrs. P. Topping Mr. T. Barker Mrs. K. Fewings Mr. I.R. Lloyd Mr. R. Turner ( Mr. S. Boyce) Mrs. H. Fishman Mr. A.H. McKnight Mr. R. Vincent Mr. M. Brechin (Mr P. Flaxman) Mr. M. Purches Mr. L. Walton Mr. M.J. Carr Mrs. P. Gordon Mrs. L. Richmond Mr. D. Williams Mrs G. Chapman Mrs. K. Hartwell Mr. S. Saunders Mr. G. Cook Mr. M. Jackson Ms. V. Seaman Mr. R.M. Cripps Mrs. A.J. Jewitt Mr. K. Schofield

vi Members of Department

Academic Visitors (1st Oct 2003 – 30th Sept 2004) Altay, Ms Arzu, Univ Minnesota, USA Latif, Miss Sofia, Department of Physics, Oxford Anantharaman, Prof TR, Ashram Atmadeep, India Liu, Mr Guo-Qiang, Chinese Acad Sciences, Beijing Audebert, Dr Fernando, Buenos Aires Univ, Argentina Liu, Prof Bang-Gui, Chinese Acad Sciences, Beijing Barjaktevic, Mr John Paul, Univ Queensland, Australia Ma, Dr Yong-Qing, Oxford Univ Dept Materials Bhatti, Dr Rashid, QinetiQ Mukhopadhyay, Dr Sangamitra, Inter-Univs Indora, India Bishop, Dr Catherine, MIT, USA Nguyen-Manh, Dr. Duc, UKAEA Bishop, Dr Hugh, MIMIV Ltd, Abingdon Nzula, Miss Miyelani "Miemi", Cape Town Univ, S Africa Brown, Dr Heather Lea, Univ Minnesota, USA Oh, Dr Jun Cheol, Ctr for Adv Aerospace Matls, Korea Butler, Dr Paul, Crown Cork & Seal Co Inc, Wantage Özer, Dr Özgur, Univ Bilkent, Ankara, Turkey Calin, Mr Daniel M, NTNU, Trondheim, Norway Peng, Prof Lian-Mao, Chinese Acad Sciences, Beijing Canzian, Mr F, Venice Univ, Italy Pethica, Prof John, Trinity College Dublin Cawkwell, Mr Marc, Univ Pennsylvania, USA Phasha, Mr Maje, Univ of the North, Sovenga, S Africa Chang, Miss Lan-Yung, Univ Cambridge, UK Rayment, Dr Tim, Begbroke Directorate Chauke, HR, Univ. of the North, South Africa Reddy, Dr B, Oxford Univ Dept Materials Deneen, Ms Julia, Univ Minnesota, USA Rejec, Dr Tomaz, Ljubljana Univ, Slovenia Dong, Dr Hongbiao, Imperial College London Ross, Prof Caroline, MIT, USA Doyle, Dr Tony, Doyle & Tratt Products Ltd, Horsham Ryves, Mr Luke, Univ Sydney, Australia Dudarev, Dr Sergei, UKAEA Sachlos, Mr Eleftherios, Begbroke Directorate Eyre, Prof Brian, Chair, CLRC, Rutherford Appleton Lab Sanchez, Ms Maria, Rey Juan Carlos Univ, Madrid, Spain Fairchild, Mr John, Forensic Alliance, Culham Science Centre Schneider, Dr André, Max-Planck Inst Iron Res, Dusseldorf Falster, Dr Robert, MEMC Electronic Materials, Italy Schönberger, Dr Uwe, Max-Planck Inst, Stuttgart Finnis, Prof Mike, Queen's Univ Belfast Smith, Dr Jason, Heriot-Watt Univ, Scotland Gabrys, Dr Barbara, Oxford Univ Dept Continuing Education Smith, Dr Peter, GCHQ Garmendia, Dr Iñaki, Inasmet, San Sebastian, Spain Song, Dr Se Ahn, Samsung, Korea Gilliss, Ms Shelley, Univ Minnesota, USA Swan, Mr Mark, Radcliffe Infirmary, Oxford Gilmore, Mr Joel, Univ Queensland, Australia Vesely, Dr Drahosh, OCAMAC Fellow Harding, Dr John, UCL Visart de Bocarmé, Dr Thierry, Free Univ Brussels, Belgium Hashimoto, Dr A, Natl Inst Adv Science/Technol, Tsukuba Vitek, Prof Vasek, Univ Pennsylvania, USA Hauzay, Mr Pierre, Ecoles des Mines de Nancy, France Wang, Prof Enge, Chinese Acad Sciences, Beijing Hayashi, Dr Toshiaki, NTT Labs, Japan Warren, Dr Paul D, Pilkington Hernandez-Mayoral, Ms M, CIEMAT, Madrid Univ, Spain Whitehouse, Prof Colin, CCLRC Rutherford Appleton Lab Holdway, Dr Philip, QinetiQ Wood, Prof John, CCLRC Rutherford Appleton Lab Imeson, Dr Doug, DSTL Wu, Dr Houzheng, Coventry Univ Jefferson, Prof JH, Qinetiq Xiong, Dr Xiangyuan, Monash Univ, Australia Jiansirisomboon, Dr S, Chiang Mai Univ, Thailand Yang, Dr Chunhui (Susan), Harbin Inst Technology, China Kamaya, Dr Masauyki, Inst Nuclear Safety Sys, Fukui, Japan Yang, Prof Haitao, Wuhan Univ Technol, China Karlsson, Ms Lisa, Lund Univ, Sweden Yi, Prof Jianhong, Central South Univ, Hunan, China Kovac, Dr Pavol, Slovak Acad Sciences, Bratislava Zhang, Dr Fucheng, Yanshan Univ, Qinhuangdao, China Kugler, Prof Sandor, Budapest Univ Technol/Econ, Hungary Zhang, Prof Fucheng, Yanshan Univ, China La, Dr Peiqing, Lanzhou Inst Chem Phys, China Zhen, Dr Zisheng, Univ Sci & Technol, Beijing, China Alumni Association Committee Dr. M.J. Archer, Commercial Director, BWE Ltd. Dr. G.R. Armstrong, Chief Materials Engineer, Goodrich Actuation Systems / Lucas Aerospace Dr. E. Boswell, Procter and Gamble Dr. M.H. Burden OBE, Technical Director, Dowty Aerospace Propellers Mr. H. Dickinson, MD, Norton Aluminium Products Ltd. Professor R.D. Doherty, Drexel University Dr. K.M. Fisher, President-Marketing Europe, Busak+Shamban UK Mr. A. Geddes, Metal Agencies UK Ltd / Viohalco Group Greece Dr. D. Gooch Mr. N.P. Gregory, Abingdon School Mr Andrew MacLeod, CEO EMEA, MCI Mr. D.K. McLachlan, formerly Tax partner Price Waterhouse Coopers Dr. K.A.Q. O’Reilly, Department of Materials, University of Oxford Mr. C.G. Purnell, formerly Technical Director, Brico Engineering Miss L. Scruby, trainee teacher Mr. R. Strawson, Head of Physics, Abingdon School Professor G.D.W. Smith, FRS, Department of Materials, University of Oxford

vii Research in Progress 2004-2005

Industrial Advisory Panel Dr. A. Begg, Chief Executive, The Automotive Academy Mr. P. Bradstock OBE, Director, Paul Bradstock Consulting Dr. M. Clark, Director, Fanwood Ltd Dr C. Elliott, Director of Supply Chain, Corus Strip Products, UK Dr S. Garwood, Director of Technology, Aerospace Dept., Rolls Royce plc Professor B.L. Eyre, CBE, FREng, formerly Chairman CCLRC Dr. S. Garwood, Director of Technolgy, Aerospace, Rolls-Royce Plc. Mr. R. Malthouse, Group Secretary, Cookson Group Dr. C.C. Morehouse, Director, Information Storage Technology Lab, Hewlett-Packard USA (Committee Chairman) Dr. J. Patterson, Head of Fuel Cycle Technology, British Nuclear Fuels Professor C.J. Peel, Director, Technology (Strategy), FST, QinetiQ Ltd Prof. Y. Tsukahara, Toppan Printing Co., Japan

Research Sponsors

Much of the research in the department is supported by grants from Research Councils, industrial companies, government departments, overseas governments, trusts and charitable foundations, learned societies and city livery companies. The department is greatly indebted to these organisations for their generous support.

Alcan International Ltd JEOL UK Ltd Alcoa Extrusions Johnson Matthey Armourers and Brasiers Company BNFL Leverhulme Trust British Council Luxfer Group Ltd British National Space Agency MEMC Chinese Government Morgan Crucibles Ltd. Clarendon Fund National Physical Laboratory Cookson Group N-Tec Ltd. Corus NSF Crown Cork & Seal Oji Paper Co. Daphne Jackson Trust ORS DARPA Osprey Metals Ltd DRA Oxford Applied Research DSTL Oxford Nanoscience Ltd DTi Oxonica Dupont Princeton Materials Institute EPSRC Qinetiq EU Regenesys Faraday Partnership Rhodes Foundation Ford Motor Co Rolls Royce plc Helsinki Univertiy of Technology Royal Academy of Engineering Hardide Scatchered Scholarship, Merton College Health and Safety Executive Seagate Technology Ltd Hewlett-Packard Sulzer Metco Higher Education Funding Council for England Thai Government Hitachi Europe The Royal Society INSS Toppan Printing Company Institute of Materials UKAEA Ironmongers Company Wellcome Trust

viii Profiles of Senior Staff Profiles of Academic Staff

Dr. Hazel Assender Lecturer in Materials Linacre College Research, both experimental and modelling, on a range of polymer and polymer composite materials. Particular areas of interest include the relationship between processing and microstructure, surface characterisation and modification, and polymer coatings and thin films.

Dr. Simon Benjamin Royal Society University Research Fellow Exeter College Physics of computation. Design and realization of architectures for new forms of information processing, especially quantum computing. Theoretical work relating to the design, growth and characterization of solid state nanostructures for computation, with particular current emphasis on (a) quantum dots systems, both self assembled and lithographically defined, and (b) fullerene systems (nanotubes, endohedral C60, etc.) Secondary interest in other areas of quantum information theory, such as quantum game theory.

Dr. Roger Booker Emeritus Reader in Electronic Materials Wolfson College OCAMAC Senior Fellow Microscopic studies of semiconductor materials and devices and the effects of structures on properties.

Professor Andrew Briggs Professor of Nanomaterials Wolfson College Director of the Quantum Information Processing IRC Director of Quantum Information Processing Interdisciplinary Research Collaboration. • Holliday Prize, Institute of Materials, 1984 • Metrology award for World Class Manufacturing, 1999 • Honorary Fellow of Royal Microscopical Society, 2000

Professor Sir Richard Brook OBE FREng Emeritus Professor St Cross College Processing and properties of ceramic materials.

[ Currently Director of the Leverhulme Trust]

ix Research in Progress 2004-2005

Dr. David Bucknall Lecturer in Materials

Structure and morphology of polymers. Effects of molecular architecture on polymer diffusion and structure. Influence of external fields in determining and controlling chain orientation and segregation behaviour. The structure and dynamics of polyrotaxanes. Nano- scale molecular devices derived from polyrotaxanes. Use of neutron reflection and ion beam depth profiling techniques for studying surfaces and interfaces. Non-conventional lithography using polymers. Microfluidics. Digital ink-jet technology.

Dr. Martin Castell CPhys Royal Society University Research Fellow Wolfson College Elevated temperature scanning tunnelling microscopy of oxide surfaces to identify atomic scale defects relevant to catalytic processes and nanotechnology. Investigation of patterned oxide surfaces for use as templates in nanoelectronics. High resolution secondary electron imaging in the SEM of semiconductor nanostructures and devices to study local strain, dopant distributions, dopant diffusion and deactivation.

Professor Alfred Cerezo Professor of Materials Wolfson College Investigations of solid state phase transformations on the atomic scale by a combination of high resolution microscopy and computer modelling. Development of atom probe microanalysis and its application to a range of materials. • E.W.Müller Outstanding Young Scientist Award, Int. Field Emission Soc. 1988 • C.R. Burch Prize, British Vacuum Council, 1990 • Sir George Beilby Medal and Prize, 2001 • NPL National Award for Innovation in Measurement 2004

Professor David Cockayne FRS, FInstP, FAInstP Professor in the Linacre College Physical Examination of Materials Development of electron optical techniques for investigating structure of materials; defects in crystalline material; structure of amorphous materials; refinement of structures including quantum dots and interfaces ; remote microscopy.

• President of the International Federation of Societies of Microscopy, 2003-7.

Dr. Jan Czernuszka Lecturer in Materials Trinity College Interaction of biochemicals with ceramics. Formation of nanolaminates, composites and coatings at room temperature. Development of novel bone analogues, drug delivery systems and hierachically controlled structures. Mechanical properties of natural materials. Tissue engineering of scaffolds. • CBI / Toshiba Year of Invention, winner of University section, 1993

Professor Patrick Grant Cookson Professor of Materials Processing Linacre College Director of OCAMAC Director of Faraday Partnership Advanced processing of materials, such as spray forming of metals, composites and coatings. Research has focused on the relationship between heat and mass flows and microstructures. On-line monitoring and numerical simulations are used to help understand the underlying process physics.

x Profiles of Senior Staff

Dr. Nicole Grobert Royal Society Dorothy Hodgkin Fellow

Production of carbon nanotubes and modified carbon nanotubes by chemical vapour techniques. In-situ investigation and characterisation of nanotube growth in order to elucidate important parameters for the controlled formation of carbon nanotubes and related materials.

• Pergamon Prize 2001

Professor Chris Grovenor Professor of Materials St Anne’s College Deputy Head of Department Applied superconductivity and the processing of electronic materials, and leader of the group developing applications for our new CAMAC NANOSIMS 50.. Other recent work has focused on understanding the fundamental limitations in the processing of high temperature superconducting materials and developing techniques for reliable preparation of HTS components. The deposition and characterisation of nano-structured oxide films for gas permeation and photovoltaic electrode applications has been a growing area of interest.

Professor Sir Peter Hirsch FRS, Hon. FIMMM Emeritus Professor St Edmund Hall Electron microscopy of defects in crystals and modelling mechanical properties of crystalline materials in terms of dislocation processes. Recent interests include modelling the brittle- ductile transition and plastic properties of intermetallics. • Royal Society : Hughes Medal 1973 and Royal Medal, 1977. • Metals Society Platinum Medal 1976 • Wolf Prize in Physics, 1983 • Acta Metallurgica Gold Medal, 1997

Professor John Hunt FRS Emeritus Professor St Edmund Hall Modelling and understanding fundamental solidification processes: This has included work on eutectics, peritectics, cellular and dendritic growth. The fundamental understanding has been applied to casting processes. Recent work includes experimental and theoretical studies of twin-roll casting and differential scanning calorimetry. • The Royal Society Armourers and Brazier's Award, 2001. • The Bruce Chalmers Award, TMS AIME, 1996. • Rosenhain Medal and Prize, Institute of Materials, 1981. • C.H. Mathewson Gold Medal, TMS AIME,, 1967. Dr. John Hutchison Reader in Materials Wolfson College Development of high resolution electron microscopy for structural characterisation of new materials including : quantum dots, inorganic fullerenes and complex oxides. Development of controlled environment electron microscopy for in-situ study of catalysts and of gas-solid reactions. Development and applications of aberration-corrected HREM. • Glauert Medal, Royal Microscopical Society, 1975 • President, Royal Microscopical Society, 2002

Dr. Mike Jenkins Reader in Materials Trinity College Director of Electron Microscope Facilities

Radiation damage, transmission electron microscopy, phase stability under irradiation, stress corrosion cracking, intermetallics. Recent work has focused on fundamental mechanisms of radiation damage, especially displacement cascade processes, mechanisms of embrittlement of pressure vessel steels, and new methods for characterizing small defect clusters.

xi Research in Progress 2004-2005

Dr. Angus Kirkland Leverhulme Senior Research Lecturer Linacre College Ultra High Resolution Transmission Electron Microscopy. Image Simulation and Processing. The investigation of new approaches to quantitative microscopy (theory and experiment). Structural studies of nanocrystals, inorganic oxides and surfaces. The development of new detectors for imaging with high energy electrons.

Dr. John Martin Sc. D, C. Eng., FIMMM Emeritus Reader St Catherine’s College OCAMAC Senior Fellow The relationship between the structure and the properties of metallic materials, particularly precipitation hardening, recrystallization and grain growth, fatigue and fracture. • Sidney Gilchrist Thomas Medal and Prize, Institute of Materials, 1986. • Platinum Medal, Institute of Materials, 2001.

Dr. Christiane Nörenberg Royal Society Dorothy Hodgkin Fellow Wolfson College Growth of quantum nitride nanostructures (InGaN, AlGaN) by molecular beam epitaxy (MBE) and in-situ surface characteristion by elevated-temperature scanning tunnelling microscopy (STM) and electron diffraction to investigate nucleation and elucidate growth modes. Atomic-scale studies on the growth of metals on GaN surfaces. Investigations of the electronic structure of endohedral fullerenes by STM for possible applications in QIP.

Dr. Peter Northover Lecturer in Materials St Catherine’s College Practical Class Organiser Non-ferrous and precious metallurgy and metalwork in ancient and historical contexts and their experimental reproduction; engineering metallurgy of the industrial revolution; very long term stability of microstructures; interaction of buried metal with the environment.

Dr. Keyna O’Reilly Lecturer in Materials The Queen’s College Solidification processing of advanced materials from laboratory scale simulations through to pilot scale processing plant, with particular interests in grain refinement and intermetallic phase selection. Also thermal analysis of phase transformations. Covering a wide range of materials including Al alloys, intermetallics, biomaterials, and solder alloys.

Professor Amanda Petford-Long C.Phys Professor of Materials Corpus Christi College The correlation of microstructural and magnetic or optical properties of thin films with applications in information storage. The main characterisation tool is TEM, including in-situ techniques to study magnetisation mechanisms (Lorentz microscopy) in magnetic thin films, and crystallisation and growth kinetics in optical and magnetic nanocomposite films.

xii Profiles of Senior Staff

Professor John Pethica FRS Visiting Professor St Cross College Surface and nanometer scale properties of materials. Study of mechanical properties using nanoindentation and of surface atomic structure and transport processes using scanning tunnelling microscopy. Development of atom resolved AFM and force spectroscopy of single bonds. • Holweck Medal, Société Francaise de Physique & IoP, 2002. • Hughes Medal, The Royal Society, 2001. • Rosenhain Medal, Institute of Materials, 1997. • Sabbatical Chair, Sony corporation R&D, Japan, 1993-4. Professor David Pettifor FRS Isaac Wolfson Professor of Metallurgy St Edmund Hall Director of Materials Modelling Laboratory Development and application of electron theory to understanding and predicting the properties of materials, in particular metals, alloys and covalently bonded semiconductors and ceramics. • Royal Society Armourers and Brasiers’ Medal 1999 • William Hume-Rothery Award, TMS 1995. • Hume Rothery Prize, Institute of Materials, 1990.

Dr. Rosetta Plummer Department Administrator St Edmund Hall Responsible for the departmental finances, buildings, personnel management and provision of technical and secretarial services. Focal point for research agreements, development of the department's use of the Begbroke Science and Business Park, and services to industry.

Dr. Steve Roberts Reader in Materials St Edmund Hall Mechanical behaviour of materials, especially their response to surface deformation and the brittle-ductile transition. Studies aim at linking modelling at the defect and dislocation level with experimental studies of well-characterised materials.

Dr. Jeremy Sloan Royal Society University Research Fellow Wolfson College (joint with Department of Chemistry) Synthesis and low dimensional crystal growth behaviour of low dimensional materials formed within single and multi-walled carbon nanotubes. Synthesis and characterisation of inorganic fullerene-like structures. Physical properties determination.

Professor George Smith FRS Professor of Materials Trinity College Head of Department Phase transformations, atom probe analysis. Studies of the role of alloy elements and trace additions on the microstructure, heat treatment and properties of steels and non-ferrous alloys. Atomic scale studies of heterogeneous catalysts. • Acta Materialia Gold Medal 2005 • NPL National Award for Innovation in Measurement 2004 • Rosenhain Medal and Prize, 1991 • Sir George Beilby Medal and Prize, 1985

xiii Research in Progress 2004-2005

Dr. Jason Smith Lecturer in Materials Mansfield College Semiconductor nanostructures and devices, particularly for use in quantum optoelectronics and quantum information processing. Design and characterisation of novel semiconductor nanocrystals for wide ranging applications such as sensors, fluorescent labels, photovoltaics, and telecommunications. Use of optical microcavities for controlled interaction between light and matter.

Dr. Ian Stone Senior Research Fellow

Processing-microstructure relationships in alloys and metal matrix composite systems. Evolution of microstructure during the spray forming process, grain growth in the semi-solid state, deformation behaviour of semi-solid alloys. Squeeze casting and rheocasting of wrought alloys. Manufacture and characterisation of amorphous, nanocrystalline and quasicrystalline aluminium alloys.

Professor Adrian Sutton FRS FInstP FIMMM FRSC CPhys CEng Professor of Materials Linacre College Theory and Simulation of processes within materials at the atomic and microstructural level.

Dr. John Sykes Reader in Materials Mansfield College Corrosion of metals. Conversion treatments, protection by organic coatings, studies of coating breakdown. Passivity, chloride-induced pitting, corrosion of steel in concrete, metal hydrides for energy storage.

Dr. Glyn Taylor Senior Research Fellow Linacre College Mechanical properties of metallic materials, especially the deformation of single crystals. Growth of single crystals for deformation studies, bcc metals and alloys containing oxide or nitride dispersions, intermetallic compounds including γ-TiAl and various B2 compounds. Relating yield stress and strength to the properties of dislocations. Measuring elastic constants.

Professor John Titchmarsh RAE Research Professorship in St Anne’s College Microanalysis and Structural Integrity Techniques for electron microscopy materials analysis: electron energy loss spectroscopy and X-ray analysis. Mechanical properties, precipitation and segregation in nuclear reactor alloys, ferritic steels, surface engineered hard coatings and ceramic composites. Extraction of information using chemometric techniques.

xiv Profiles of Senior Staff

Dr. Richard Todd Lecturer in Materials St Catherine’s College Mechanical properties of ceramics and metals. Most research revolves around oxide ceramics, thermal residual stresses, neutron and X-ray diffraction, and superplastic metals. Current interests include the processing and mechanical properties of ceramic nanocomposites, measurement of micro-stresses in ceramics, characterisation of cold worked microstructures using diffraction peak profile analysis, and projects on the superplastic forming and diffusion bonding of commercial alloys.

• Pfeil Award, Institute of Materials, 2001. Dr. Drahosh Vesely OCAMAC Senior Fellow Wolfson College Light and electron microscopy, electron beam damage and spectroscopy are used to study crystallographic morphology of spherulitic structures, nucleation and crystallization, stabilization, degredation, electrical conductivity, fluorescence, diffusion, permeability, solubility and mechanical properties of polymeric compounds.

Professor Mike Whelan FRS Emeritus Professor Linacre College Transmission electron microscopy of materials, transmission electron diffraction of thin specimens (theory and application to crystal lattice defect observation). Reflection electron diffraction of surfaces (theory and applications to molecular beam epitaxial growth). • Distinguished Scientist Award, Microscope Society of America, 1998 • Hughes Medal, Royal Society, 1988 • C.V. Boyes Prize, Institute of Physics, 1965

Dr. Angus Wilkinson Senior Departmental Research Lecturer Corpus Christi College Mechanics at the microscopic scale, both experimental and modelling. Dislocation modelling of fatigue and fracture processes. Development of SEM based diffraction methods (ECCI and EBSD) for imaging lattice defect distributions and measuring local internal strain distributions.

Dr. Peter Wilshaw Lecturer in Materials St Anne’s College Characterisation of the electrical and mechanical properties of defects in semiconductors. Development of novel structures and materials for field emitters to be used in field emitter displays. High resolution 2D mapping of dopant distributions in semiconductors. Development of a bioactive coating for metal implant prostheses.

Professor Colin Whitehouse Visiting Professor

Council for the Central Laboratories of the Research Councils (Rutherford-Appleton and Daresbury Laboratories).

xv Research in Progress 2004-2005

Professor John Wood FREng Visiting Professor Wolfson College Industrial Fellow Chief Executive, Council for the Central Laboratories of the Research Councils (Rutherford- Appleton and Daresbury Laboratories). Materials processing, biomaterials, surface engineering, Materials Foresight, Strategic policy for large facility research.

[Professor of Materials Engineering, University of Nottingham (on secondment)]

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xvi Structure and Mechanical Properties of Metals

A. Structure and Mechanical Properties of Metals

I - MECHANICAL PROPERTIES OF STRONG SOLIDS, METALS AND ALLOYS

Fundamentals of cyclic deformation and Microsuperplasticity in aluminium alloys fatigue crack initiation J. Robinson, Dr. R.I. Todd Dr. A.J. Wilkinson, Dr. S.G. Roberts, Dr. M Legros* The origin of 'microsuperplasticity' in which fine The evolution of dislocation microstructures produced whiskers are drawn out of superplastic aluminium during cyclic deformation is being examined using alloys during fracture is being investigated. The electron channelling contrast imaging, a novel SEM whisker dimensions are being studied as a function of technique. The objective is to understand the reasons strain rate, and their structure and composition are for dislocation patterning and subsequent strain being analysed by electron optical techniques. localisation leading to the initiation and early growth of fatigue cracks. Recent work concerns Si fatigued at elevated temperatures.(*Ecole des Mines, Nancy, Surface effects in superplastic deformation France) of aluminium alloys M.A. Rust, Dr. R.I. Todd

Internal stresses and stored energy in steels The superplastic deformation of aluminium alloys is E. Clarke, Dr. A.J. Wilkinson, Dr. R.I. Todd, Dr. D. being studied with particular reference to surface Crowther*, Dr. A. Howe* observations. Aspects to be studied include the origin of surface ridges and other inhomogeneous aspects of Several methods of measuring microstresses in steels flow, co-operative grain boundary sliding, are being investigated, with a view to developing a intragranular deformation and the nature of grain robust method of measurement. The main methods to boundaries. (In collaboration with R. Butler, be tried are (i) XRD line profile analysis, (ii) EBSD, Superform) and (iii) nanoindentation. The microstresses are thought to be important in many steels, and link processing to properties in much the same way as Physical properties of Li-Mg alloys microstructural features such as grain size. (In Dr. G. Taylor, Dr. M.E. Siedersleben*, Professor S. collaboration with *CORUS and with support from Naito** EPSRC and CORUS) Thermal expansion coefficients and the values of elastic constants C11, C12 and C44 are being studied Deformation of single crystals of Nb-Zr-O over the temperature range 4-300K for alloy alloys and Nb-Zr-N alloys compositions between 40 and 70at% magnesium. Dr. P. Manyum*, Dr. G. Taylor (*Honsel Werke Reichmetalle, Germany; **Kyoto University, Japan) Single crystals of niobium zirconium alloys are being oxidised at low pressures in an ultra-high vacuum furnace to produce a zirconia dispersion. The size of Submicron surface deformation during the precipitate is controlled by a subsequent anneal at superplastic flow of the Sn-Pb eutectic alloy ~1600oC. Mechanical properties are being studied by P. Holme, Dr. Y. Huang, Dr. R.I. Todd differential tensile tests and the particle-matrix structure and dislocation-particle interactions Submicron surface markers are being deposited on the observed by transmission electron microscopy. surface of superplastic Sn-Pb alloys and will be Similar experiments on Nb-N solid solutions are examined before and after superplastic deformation. being carried out also at deformation temperatures Several interesting questions in the mechanism of well below ambient. superplastic flow will be addressed, including the importance of intragranular deformation and the nature of grain boundary sliding.

Page 1 Research In Progress 2004–2005

Development of corrosion resistant high Core structure of screw dislocations in strength ferritic steels b.c.c. metals Professor J.M. Titchmarsh, M. Briceno-Gomez, Dr. P. Professor Sir Peter Hirsch Brown* Isotropic elasticity calculations show that the High strength ferritic steels are prone to stress symmetrical 3-fold dissociation of screw dislocations corrosion cracking. This project aims to improve in b.c.c. metals is unstable. Yet atomistic computer cracking resistance by modifying the composition of calculations usually show 3-fold dissociated Ni-Mo-containing ferritic steel by selected elemental structures, dissociated mainly on {110} planes. It additions. Alloys will be made by melt spinning and turns out that using anisotropic elasticity the mechanical and corrosion properties optimised by symmetrical 3-fold dissociation of {110} is stable or systematic variation of heat treatment and metastable. A possible 6-fold dissociation will be microstructural characterisation. (*QinetiQ) (Funded investigated. by QinetiQ) Properties of Super-elastic beta Ti-Nb Multi-scale modelling and simulations of Alloys ('Gum Metal') cleavage fracture in steels Dr. A.J. Wilkinson, Dr. R.I. Todd, D. Armstrong Professor S.J. Chapman*, Dr. S.G. Roberts, Dr. J.R. Ockendon*, Dr. A.J. Wilkinson, Dr. R. A Japanese group have reported a beta-Ti alloy 'Gum Voskoboynikov, A. Kumar Metal' having very unusual mechanical properties (enormous elastic limit of ~2.5% strain, high tensile The project aims to formulate contimuum models of strength of 1-2GPa, low Young's modulus of 40-80 plastic flow in three dimensions, and to apply these to GPa). Amazingly they claim that plastic deformation crack initiation and propagation in muti-phase of Gum Metal does not involve dislocation motion. materials. The models will be keyed to experimental The project will explore the processing, structure and studies of fracture nuclei and crack-tip plastic zones in properties of Gum Metal using powder processing, steels with simplified microstrcutures. (*Oxford focused ion beam micromachining, nano-indentation, Centre for Industrial and Applied Mathematics) and electron microscopy techniques. (Funded by EPSRC) In-situ SANS investigation of cavitation in Brittle-ductile transitions in BCC metals superplastic alloys T. Joseph, Dr. S.G. Roberts, Dr. S.L. Dudarev* Dr. R.I. Todd, Dr. S. van Petegem*

The project will investigate the brittle-to-ductile The nucleation and growth of cavitation during transition in vanadium and iron-chromium alloys up superplastic deformation is being investigated using to 12%Cr (these metals are the basis for proposed Small Angle Neutron Scattering at the SINQ neutron fusion power plant alloys). Pre-cracked miniature source in Switzerland. An in situ investigation of a bend specimens of single crystals will be fracture model Sn-Pb-Cu alloy is being performed, and tested in the temperature range 77 - 450K. The effect cavitation in Al 7475 will also be investigated (*Paul of dislocation motion around the crack tips on fracture Scherrer Institute, Switzerland). stress will be examined, and modelled using dynammic-dislocation simulations. (*UKAEA Culham) (Funded by EPSRC and UKAEA)

Page 2 Structure and Mechanical Properties of Metals

II – INTERMETALLICS

Simulation of weak-beam images of defects The growth and deformation of TiAl3 in γ-TiAl single crystals C. Lang, Professor D.J.H. Cockayne, Professor Sir Dr. P. Manyum*, Dr. G. Taylor Peter Hirsch Transition metal additions to TiAl3 are being made to Weak beam images of 1/2[112> edge dislocations in stabilise the cubic structure. Single crystals will be γ-TiAl are being simulated using the CUFOUR grown and used for deformation studies.(*Suranaree programme with a view to distinguishing between University of Technology, Thailand) possible alternative structures of these defects. A model has been developed to explain the locked nature of these defects. (Funded by EPSRC) Crystal growth and mechanical properties of RuAl alloys S.J. Pak, Dr. G. Taylor Mechanical properties of lamellar TiAl and effects of purity and composition The ruthenium aluminium system forms an Dr. G. Taylor, Professor S. Naito* intermetallic compound with the B2 structure at 50 % Al. RuAl has a high melting point and the vapour Polysynthetically twinned crystals may be formed pressure of Al when the alloy is molten is sufficiently during growth of TiAl binary alloys depending on high to make the growth of single crystals difficult. A composition and growth conditions. A series of binary floating-zone crystal growth apparatus has been alloys with very high purity has been made for the constructed for operation at above ambient pressure in study of mechanical behaviour and yield stress values an attempt to grow good quality crystals of RuAl and over a range of temperatures. (*Kyoto University, other B2 intermetallic compounds. Japan) Mechanical properties of CoTi based alloy Deformation of γ-TiAl single crystals with single crystals [001] orientation L. Zhang, Dr. M.L. Jenkins, Dr. G. Taylor S.J. Pak, Dr. M.L. Jenkins, Dr. G. Taylor CoTi crystals show a yield stress anomaly Single crystals of γ-TiAl have been grown with a characteristic of certain intermetallic compounds. The [001] orientation from high purity alloys in the range peak-stress temperature and strength of the 53.5-56 at%Al. They are being deformed deformed in stoichiometric binary alloy are relatively low. The compression and also in tension over a range of addition of isostructural CoHf is expected to increase temperatures to study the yield stress anomaly and these parameters significantly. Crystal growth is mechanical twinning. Selected slices are being inhibited by the formation of Ti oxides and the analysed for dislocation content by TEM. deformation is characterised by glide of <100> dislocations.

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Page 3 Research In Progress 2004–2005

B. Non-Metallic Materials

I - CERAMICS AND COMPOSITES

Nanocomposite ceramics for technical Perovskite-based ceramic nanocomposites applications H. Wang, Dr. R.I. Todd I. Shapiro, Dr. S.G. Roberts, Dr. R.I. Todd, Professor J.M. Titchmarsh Functional ceramics based on perovskite structures have many interesting and useful properties (e.g. they The project is aimed at use of alumina - silicon can be piezo- and pyro-electric). Much research has carbide ceramic nanocomposites in applications gone into tailoring their properties to particular where wear and abrasion resistance are important. The applications by changing their composition, but project is focussed on the surface mechanical relatively little work has been done on changing their properties of sintered ceramic nanocomposites. There properties by the addition of second ceramic phases. are two main aims - (a) to understand the mechanisms Recent work in Oxford has shown that very small of their improved properties over normal alumina volume fractions (e.g. 1-2%) of nanophase additions ceramics; (b) to produce materials usable in real can have dramatic effects on the properties of industrial applications. This project is in collaboration structural ceramics, and research elsewhere gives with Morgan Matroc. (Funded by EPSRC) reason to believe that this might also be the case with functional ceramics. Furthermore, some of these effects might be synergistic in that they could improve Composites based on synthetic opal both the mechanical and the functional properties of Dr. J.L. Hutchison, Professor L.M. Sorokin* the material. The aim of the project is to explore the interaction between internal stresses, ferroelectric Novel composites have been prepared by filling the domain structure and functional and mechanical regular voids in synthetic opal by guest materials such properties of such nanocomposites, starting with the as tellurium, InSb, GaAs, etc.. The opal is a cubic- barium titanate/SiC system. (In collboration with Morgan Electro Ceramics) close-packed lattice of SiO2 spheres, and it has been found that the guest materials may be present as single-crystalline, 3-D networks, giving unusual Environmental effects on surface damage properties. (*In collaboration with the Ioffe Physical- Technical Institute, St Petersburg, Russia, supported in float glass by the Royal Society) Dr. P.D. Warren*, Dr. S.G. Roberts

The project will use high-temperature indentation Structure and properties of 'Hardide' testing to investigate the mechanisms of surface coatings damage accumulation in the float glass process, in D. Di Maio, Dr. S.G. Roberts, Dr. C.R.M. Grovenor, particular the influence of surfactants. (*Pilkington Y. Lakhotkin* plc)

A new class of ultra-hard coatings has been Wear and indentation of alumina/SiC developed. The project will investigate their structure and properties. (*Hardide Ltd.) nanocomposites A. Limpichaipanit, Dr. S.G. Roberts, Dr. R.I. Todd

High temperature strengthening of zirconia The wear and indentation of alumina/SiC ceramics nanocomposites are being investigated with a view to M.P.S. Saran, Dr. R.I. Todd explaining the reduction in size of surface pullouts and increased resistance to microcrack nucleation Transformation toughening in zirconia is lost at high observed in extensive previous work in this temperature owing to the reduction in driving force Department. (With support from the Thai for the martensitic transformation which causes it. Government) Cold pre-stressing is being explored as a method of retaining strength at high temperature. (In collaboration with Morgan Matroc)

Page 4 Non-Metallic Materials

PLZT microstructures for high strain Mullite/alumina composites for wear piezoelectric applications resistant applications M. Waring, Dr. R.I. Todd, Dr. K.P. Plucknett*, Dr. Dr. R.I. Todd, Dr. F. Zhang* L.P. Walker* Alumina/SiC nanocomposites provide step change PLZT compositions close to the tetragonal / improvements over monolithic alumina in terms of rhombohedral phase boundary are known to produce wear resistance and surface finish, but are more an exceptionally large strain for a given applied expensive to produce owing to the high temperatures electric field. There are three contributions to the and non-oxidising atmospheres required. This project strain, namely electrostriction, the converse is investigating the possibility of producing similar piezoelectric effect, and a field induced phase change. levels of property improvements using We are using electro-mechanical testing, Raman and alumina/Mullite composites, which should be much electron microscopy and XRD to develop an cheaper to produce. (*Yanshan University, China) improved understanding of these effects through a thorough study of the relationship between microstructure, and the grain size in particular, and properties. (*QinetiQ)(Supported by EPSRC)

II - BIOMEDICAL MATERIALS

Crystallographic texture determination of Mechanical properties of biocomposites calcium phosphates D. Gotora, Dr. J.T. Czernuszka Dr. P. Fewster*, Dr. J.T. Czernuszka Composites based on natural systems are being made Novel off-axis X-ray diffraction techniques and and their dynamic mechanical and fracture response modelling are being used to determine phase determined. New models of how this class of orientation, morphology and purity. Comparison with materials deform are being formulated. (Funded by other techniques will be made throughout. (*Philips the Rhodes Trust) Research Labs) Macro-assembled spheres of apatite Design and fabrication of ceramic: Q.Xu, O. King, Dr. J.T. Czernuszka biochemical: polymer composites Dr. J.T. Czernuszka, Professor E. Bres*, Professor W. Lipid spheres are being coated with apatite which are Hosseini** then deposited on to metallic surfaces. We have hierarchical control of the macro-assembly on 5 Additions of biochemicals, such as amino acids or length scales. The liposomes are being filled with lipids, either to the growth medium or onto the surface pharmaceutical agents, such as anti-biotics and of polymeric substrates influence strongly the growth factors. (Funded by Dorothy Hodgkins morphology and crystallographic orientation of Scholarship, EPSRC) deposited ceramics. This is being used to create tailored composites and structures.(*University of In vitro approaches to bone formation Lille; **University of Strasbourg) Professor J.T. Triffitt*, Dr. J.T. Czernuszka, Dr. E. Sachlos** In situ formation and electrodeposition of active coatings Processes are being developed that encourage bone formation on a laboratory scale. The control and Q.Xu, O. King, Dr. J.T. Czernuszka manipulation of osteoblasts is of the utmost importance. (*Nuffield Department of Orthopaedic Electric fields are used to regulate the precipitation Surgery; **Begbroke Technolgy Centre) (Funded by rates of sparingly soluble solids. Biologically active Wellcome Trust and in collaboration with MRC Bone coatings have been fabricated and we are now Research Lab.) extending the process to other systems. (Funded by EPSRC)

Page 5 Research In Progress 2004–2005

Nanolaminated composites Three Dimensional Scaffolds for Tissue Dr. J.T. Czernuszka Engineering D. Wahl, Dr. E. Sachlos*, Dr. J.T. Czernuszka, Biochemicals are reacted with inorganic salts to form Professor Z.F. Cui**, Professor B. Derby***, N. layered structures compromising alternating Reis*** monomolecular sheets of biochemicals and ceramic monolayers. These materials possess novel ferro- Scaffolds are being fabricated using novel ink jet electric, elastic and optical properties. printing techniques. The mesostructure is being tailored to encourage vascularisation and subsequent tissue incorporation. The nanostructure, Modelling phospholipid monolayers at the microstructure and mesostructure are all being alveolar interface tailored to optimise the degradation rate and Dr. I. Gentle*, Dr. D.G. Bucknall mechanical properties. (*Begbroke Technolgy Centre; **Dept. Engineering Science, University of Oxford; Phosphatidylcholine molecules play an important role ***Manchester Materials Science Centre) (Funded by in the action of natural lung surfactants by supplying EPSRC and the Wellcome Trust) lipids to the alveolar monolayer. The exact mechanism for this process remains uncertain. Using self-assembling layers in a Langmuir-Blodgett Tissue Engineering of Heart Valves apparatus, surface pressure, neutron reflectivity and Dr. E. Sachlos*, Dr. J.T. Czernuszka, Professor Sir Brewster angle microscopy studies of the Magdi Yacoub**, Dr. P. Taylor**, Dr. A. Chester**, compression-expansion cycles of these systems is S. Dreger**, G. Karney being used to investigate the physiological behaviour within a lung. (*Department of Chemistry, Scaffolds for the tissue engineering of heart valves are Queensland University) (Funded by Australian being fabricated using our novel fabrication route. Government) The scaffolds are seeded with interstitial (and other) cells and their perfomance monitored. (*Begbroke Technolgy Centre; **Harefield Hospital) Tissue Engineering and three-dimensional scaffolds Cleft palate repair Dr. E. Sachlos*, D.Wahl, M. Howells, G Karney, Dr. J.T. Czernuszka, Professor Z.F. Cui**, Professor B. M. Swann*, T. Goodacre**, Profesor J. Meakin*, Dr. Derby*** D.G. Bucknall, Dr. J.T. Czernuszka

A three dimensional printing method is being The project aims to create a tissue expander to repair developed to promote the alignment, proliferation and cleft palates are other similar congenital deformities. differentiation of cells. The project will examine (*Nuffield Dept of Surgery, **Dept of Plastic various cell types. (*Begbroke Technolgy Centre; Surgery) **Dept of Engineering Science; ***UMIST) Understanding Bioselective Surfaces and An improved bone-implant interface their Medically Relevant Ligands A. Walpole, C. Wilson, Professor V. Baranauskas*, Dr. D.G. Bucknall, H. Womersley, D.J.T. Vaux* Dr. P.R. Wilshaw This project is an interdisciplinary study of the surface A new coating for metal implant prostheses is being interactions of medically important proteins and cell developed. This entails bonding a layer of porous membranes with defined polymer surfaces. The alumina to the metal surface and filling the pores with project involves the application of molecular a bioactive material such as bioactive glass. It is biological techniques to generate constrained peptide hoped that in this way the strength of the interface libraries for screening interactions with specially between the bone and implant will be improved whilst prepared defined polymer surfaces. Candidate the mechanical properties of the implant are peptide-surface interactions will be further maintained. (*Faculdade de Engenharia ElŽtrica e de characterised by both physical and cell biological Computa ‹o, Universidade Estadual de Campinas, methods. (*Dunn School of Pathology, University of Brazil) Oxford)

Page 6 Non-Metallic Materials

III - POLYMERS

Real time studies of polymer interfaces Electric Field Induced Orientation of Dr. D.G. Bucknall, Dr. S.A. Butler*, Professor J.S. Zwitterionic Telechelic Polymers Higgins** J. Xu, Dr. D.G. Bucknall, Dr. L.R. Hutchings*, Professor R.W. Richards* This project is developing the methodology, techniques and apparatus required to conduct neutron Zwitterionic telechelic polymers are ionomers with reflection experiments in real time. The technique has oppositely charged end-groups, which in solution can been applied to investigate the diffusion of oligomers cluster into aggregates or behave as single chains and plasticisers into polymers and to study the depending on the polarity of the solution. We have subsequent dissolution of the polymer films. This is been using electro-optic Kerr birefringence to the first time that such measurements have been understand the complex solution properties of these successfully carried out in real time, providing new novel polymers. Due to the presence of the permanent information and insight into the processes involved. dipoles on the chain ends orientation effects are (*Department of Chemistry, Cambridge University; highly sensitive to aggregation behaviour allowing **Department of Chemical Engineering, Imperial different field alignment effects to occur. The College) (Funded by EPSRC) segmental orientation of the chain therefore acts to produce an optical switch. (*IRC in Polymer Science and Technology, Durham University) (Funded by Structure and dynamics of polyrotaxanes EPSRC) Dr. D.G. Bucknall, Professor H.W. Beckham*

Polyrotaxanes are novel polymers which consist of Nano-structures derived from macrocycles treaded onto the polymer chain. The polyrotaxanes incorporation of these rings on the chain can have a Dr. D.G. Bucknall, Professor H.W. Beckham*, H.L. dramatic effect on the physical properties as observed Anderson** by its structure and dynamics. Using a combination of solid state NMR, quasi-elastic and small angle Polyrotaxanes are polymers which have been threaded neutron scattering, and X-ray diffraction the by macrocyclic rings, which can have a dramatic molecular basis for these physical changes are being effect on the properties of the polymer. We are investigated. (*Department of Textile and Fiber exploring the use of polyrotaxanes as a synthetic route Engineering, Georgia Institute of Technology) to forming molecular scale devices which can mimic (Funded by NATO) the behaviour of switches, magnetic memory disks and circuit wiring. Polyrotaxanes have potential to be Luminescent Conjugated Polyrotaxanes exploited in a number of these molecular scale devices by manipulation of the polymer and Dr. H.L. Anderson*, Dr. D.G. Bucknall, Dr. F. macrocycle chemistry. (*Department of Textile and Cacialli**, Professor R.H. Friend** Fiber Engineering, Georgia Institute of Technology; **Dyson Perrins Lab, Oxford University) Conjugated polymers have many potential applications, particularly as organic semi-conductors and electroluminescent display materials. We are Oxidative degradation of polymers developing a way of improving the luminescence, L. Castro-Diaz, Dr. D. Vesely, Dr. H.E. Assender stability and processability of these polymers by insulating with threaded macrocyclic rings to form The mechanism of oxidation is investigated from the polyrotaxanes. This work represents the first use of point of view of formation and diffusion of free rotaxane formation to control the optoelectronic radicals. Dispersion, solubility and diffusion of anti- properties of a conjugated polymer chain, by oxidants are correlated with Oxidation Induction Time isolating, insulating and encapsulating it. These new test for different antioxidants. Evaporation and materials will provide fundamental insights into the degradation of anti-oxidants, as well as oxidation rates behaviour of conjugated polymers by controlling of polyolefins in different halogen environments are inter-chain separation, so blocking short-range inter- investigated. The main aim is the explanation of the chain processes. (*Dyson Perrins Lab., Oxford mechanism in which the oxidation results in loss of University; **Cavendish Lab, Cambridge University) mechanical properties. (Funded by Linacre College (Funded by EPSRC) and Regenesys)

Page 7 Research In Progress 2004–2005

Diffusion and solubility in polymers Gloss of polymers G. Bernardo, Dr. D.Vesely, Dr. D.G. Bucknall Dr. H.E. Assender

Accurate measurement of diffusion rates, solubilities The gloss of a material is a measure of the specular and concentration profiles are used to establish reflectance of light from the surface. The gloss thermodynamical parameters, which can explain the depends upon the roughness of the surface. AFM observed mechanism of diffusion process. Polymer examination of a range of polymer surfaces is being solvents, as well as compatible polymers with upper applied to allow quantitative analysis of the roughness and lower critical solubility temperatures are to link the topography of a surface to the measured investigated. Two component phase diagrams are gloss. Related scanning force microscopy techniques, compared with three component phase diagrams, in such as UFM, are used to monitor the morphological which the third component is a solvent or a origin of the roughness. compatibilizer. The results are used to advance our understanding of the formation of microstructure in immiscible, miscible and compatibilized polymer Effects of molecular architecture on systems. polymer interdiffusion Dr. D.G. Bucknall, Dr. N. Clarke*, Dr. J.H.G. Vacuum Web processing Steinke**, Professor J.S. Higgins***, Dr. R. Thompson**** Dr. H.E. Assender, Dr. B.M. Henry Although the idea of polymer diffusion via reptation We have recently purchased a unique vacuum web is well understood for linear polymers, the same is not processing capability. The coater can run a 30cm so true for non-linear polymers. This project is polymer web at speeds of up to 5m/s to allow the studying the effect of molecular architecture on the deposition of multiple layers from the following diffusion process for a set of chemically identical sources: i) aluminium evaporator, ii) dual magnetron polymers, and using this model system to interpret the sputter, iii) plasma iv) flash evaporation of organic behaviour under the framework of the reptation materials with UV cure. Films can be produced for model. (*Department of Chemistry, Durham applications such as controlled optical properties and University; **Department of Chemistry, Imperial surface finish, high and low energy surfaces, barrier College; ***Department of Chemical Engineering, layers or biocompatibilisation. Imperial College; ****Dept of Chemistry, Durham University) Diffusion in composite materials M. Zhu, Dr. D. Vesely, Dr. D.G. Bucknall Microstructure of polymeric materials Dr. D. Vesely Diffusion of compounds through inhomogeneous polymeric materials is investigated from the point of The structures of amorphous and crystalline polymers view of diffusion rate and solubility. The size and are studied by light and electron microscopy. New distribution of the second phase is taken into account techniques, which overcome and/or utilize the for the calculation of the diffusion path and for the electron beam damage are developed. These permeability. Several diffusion mechanisms are techniques, which include microdiffraction, STEM considered and compared with the experimental dark field imaging, mass loss measurements, selective results. staining and chemical analysis are used to obtain more information on the molecular arrangement in amorphous and crystalline polymers. The aim of this Patternation of Polymer Thin Films work is to understand the effect of micro-structure on Dr. D.G. Bucknall, Professor G.A.D. Briggs, T. the mechanical properties of polymer systems and Okayasu composites.

Thin polymer films can demonstrate interesting dewetting behaviour on non-wetting surfaces. By Ion beam lithography capping such unstable thin films by thick rigid layers Dr. G.W. Grime*, Dr. I. Gomez-Morilla*, Dr. D.G. this dewetting can be prevented. By selectively Bucknall capping these inherently unstable thin films by semi- rigid capping layers it is possible to produce a surface The use of medium energy ion beams is being topology with a random wave morphology. This investigated as an alternative method of producing project aims to understand this phenomena and ways high aspect ration topographic patterning. The use of to control the feature size and more particularly both patterned masks as well as micro-focussed anisotropy of the resulting structures. probes is being investigated to produce not only 2D as well as 3D structures. (*Department of Physics, University of Surrey)

Page 8 Non-Metallic Materials

Long range ordering of block copolymer IMAGE-IN: Improved Ink Jet Printing by Professor R. Register*, Dr. P. Chaikin*, J. Waller, Control of Ink Media Interactions Dr. D.G. Bucknall Dr. D.G. Bucknall, Professor G.A.D. Briggs, Dr. A. Dupuis, Dr. J. Leopoldes, Dr. S. Wilkins, Dr. J. Block copolymers are being actively studied due to Yeomans, members of AGFA-Gevaert, Ardeje, Coates their inherent self-assembly characteristics, from Electrographics, Dotrix, Teich and Universite Joseph which well defined repeating or crystallographic Fourier. structures can be produced. The ability to control these structures over large length scales necessary for This project addresses industrial ink jet printing making useful devices has yet to be developed and technology with a strong innovative approach of this project is part of a larger effort to achieve this bringing together a pan-European partnership of goal. One of the principle objectives of the research is expertise along the entire technological and scientific to investigate methods for producing long range chain of inks, media, and hard- and software lateral ordering of spherical phase forming block integration, underpinned by a strong scientific copolymers in thin polymer films. A number of research programme. The project uses a holistic methods will be investigated including use of applied approach to the scientific understanding of electric or magnetic fields as well as thermal commercial and industrial ink jet technology from ink gradients, all of which are known to influence the composition, through ink jet ejection, surface structure of copolymers. The external fields will be treatment methods and subsequent ink-substrate applied to the copolymers whilst they are in the melt interaction to final print quality characteristics. (see state and above the order-disorder phase transition, www.imagein.org for further details) and should allow us to impose long range ordering behaviour desired. In order to understand how to control this field induced ordering a wide parameter Behaviour of model polymers under space in terms of copolymer molecular weight, film external fields thickness, annealing temperatures, field strength and Dr. D.G. Bucknall, Dr. L Lauro-Taroni, Dr. B. surface topography of the substrate will be Gabrys* investigated. (*Princeton University, USA) The solution behaviour of nano-assemblies of Coating polymer films telechelic polymers (model systems for ionomers and polyelectrolytes) is being studied using D. Howells, Dr. H.E. Assender, Dr. B.M. Henry, Dr. complementary light, X-ray and neutron scattering, C. Borman* combined with molecular dynamic simulations. The concentration dependence of the telechelic polymer The project seeks to improve understanding and morphology and dynamics will be studied not only control the influence of a polyester substrate on theoretically but also by development of time- subsequent coatings. The work would seek to identify resolved static scattering experiments. This work is factors that control the performance of a film as a extending to include modelling of polymers using a substrate for subsequent coating, and to try various number of theoretical methods including Monte Carlo surface pretreatments to monitor their characteristics calculations. (*Department of Continuing Education, and effect. One major consideration will be the role University of Oxford) (Partially from Daphne Jackson of the topography of the substrate on subsequent Fellowship for LLT) coating performance. (*DuPont Teijin Films) (Funded by DuPont Teijin Films and EPSRC) Microfluidic phase mixing and demixing Polymer-Plasticiser Diffusion Dr. D.G. Bucknall, Dr. J. Yeomans*, Professor A. Balazs** Dr. D.G. Bucknall, Dr. S.A. Butler*, Professor J.S. Higgins** Phase mixing and demixing of binary mixtures is being investigated in confined systems where the The ingress and egress of plasticisers in polymer thin volume of the fluid is potentially as little as a few films is being studied using detailed depth profiling microlitres. Theoretical models have been established techniques (neutron scattering and dynamic SIMS) to simulate fluid mixing of oligomer blends and coupled with microscopic IR mapping. Detailed binary fluids when confined between chemically analysis of the evaluation of the plasticiser heterogeneous surfaces. These models will be tested concentration profile and interfacial profile is being experimentally using microfluidic devices and then mapped and compared to diffusion theories of small the system extended to study demixing processes. molecule penetrants in high molecule weight (*Department of Theoretical Physics, Oxford matrices. (*Department of Chemical Engineering, University, **Department of Physics, Pittsburgh Cambridge University, **Department of Chemical University, USA) Engineering, Imperial College).

Page 9 Research In Progress 2004–2005

Network formation in epoxy/amine resins Surface crystallisation of polymers D.L. Morgan, Dr. H.E. Assender K. Shinotsuka, Dr. H.E. Assender

The formation of the network structure during the Under controlled annealing conditions, novel cure of a thermosetting resin depends on the relative crystalline morphology has been observed in heat- reaction rates of the functional groups available, these treated PET films. This may be associated with a are determined by the kinetics of the pure reaction depressed surface glass transition temperature chemistry and increasingly as the material gels the allowing surface-specific crystallisation processes. availability of reactive groups. FTIR spectroscopy We are investigating this observed phenomenon and DSC analysis are used to study these reaction further with a wider range of polyester materials to processes on a series of model compounds to establish the origin of the observation. (Funded by Oji determine the network structure that results. Paper Co Ltd.)

IV - PHOTOVOLTAIC MATERIALS

The optoelectronics of organic photovoltaic Deposition and characterisation of nanomaterials. porous conducting oxide films A. Barkhouse, K. Kawata, Dr. H.E. Assender Z. Xie, Dr. B.M. Henry, K. Kawata, Professor C.R.M. Grovenor This work focusses on the design and characterisation of a nanocomposite organic/inorganic photovoltaic Conducting, transparent electrodes are a necessary material. The optoelectronic behaviour of the various component in polymer photovoltaic devices. The materials under investigation is being characterised compatibility and interfacial electronic properties of (Supported by Toppan Printing Company Ltd.) oxide/polymer electrolyte composites are critical factors in determining the efficiency of these devices. This project is exploring sputtering, evaporation, sol- Device manufacture and characterisation gel and anodising techniques to fabricate thin films of organic photovoltaic materials with controlled microstructure. The electrical Dr. K.R. Kirov, Dr. H.E. Assender properties of the films, and their compatibility with new functional polymers, is also being studied and An organic-inorganic nanocomposite photovoltaic correlated with the nanostructure of the films material is being designed and characterised. This investigated by SEM, HRTEM and AFM. (Supported work seeks to characterise the various materials by the Toppan Printing Company Ltd.) components in the device, with particular emphasis on the organic components and interfaces, and to Modelling photovoltaic devices improve the device manufacturing processes for lab- scale testing. (Supported by the Toppan Printing C. Martin, Dr. V.M. Burlakov, Dr. H.E. Assender Company Ltd.) We will identify an simulate the key elements in the operation of a polymer/TiO2 photovoltaic device. In Synthesis of novel organic materials for particular we are investigating the role of photovoltaic devices microstructure and electric field effects on the charge B. Lochab*, Dr. H.E. Assender, Dr. P.L. Burn* transport in the composite material. (Funded by EPSRC and the Toppan Priniting Company) For the development of novel organic photovoltaic materials, various organic materials will be synthesised for the construction of nanoscale architechtures and improved device performance. (*Dyson Perrins Laboratory, Oxford University) (Supported by the Toppan Printing Company Ltd.)

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Page 10 Electronic Materials and Devices

C. Electronic Materials and Devices

I - SUPERCONDUCTING MATERIALS

During the last few years very exciting advances have led to the development of new oxide materials which superconduct at temperatures up to 160K. The Department of Materials has been working for the past 10 years on fabricating and characterizing bulk and thin film materials in collaboration with other University Departments and Industry. The aim of this work is to develop reliable processing techniques for materials fabrication, to understand the fundamental relationships between microstructure and properties and to investigate the potential of these materials for commercial exploitation.

Microstructural characterisation of Development of electroepitaxy as a novel superconducting materials method for the production of textured Dr. H. Wu*, Dr. S. Speller, C.J. Dark, S. Latif, metallic substrates for superconducting Professor C.R.M. Grovenor tapes R.M. Whiteley, Professor C.R.M. Grovenor, Dr. J.M. Superconducting ceramic samples fabricated in thin Sykes film and wire form are being characterised by X-ray diffraction and electron microscopic techniques. Of We have recently demonstrated that electrodeposition particular interest is the determination of the phase of metallic layers on a textured substrate is a powerful distribution and alignment, grain boundary structure way of growing epitaxial buffer layers of the kind and chemistry, and impurity phase chemistry in required in second generation high temperature materials prepared both within the University and by a superconducting tapes. We are currently studying the number of collaborators, and the correlation of these deposition of Ag/Ni and Ag/diffusion barrier/Ni layer features with critical current measurements. High combinations in order to demonstrate the resolution and analytical TEM, XRD texture analysis compatibility of these structures with in-situ deposited and orientation imaging microscopy techniques are superconducting layers from collaborators in being used to study the key microstructural features - Germany and Cambridge. At the same time, the especially the grain boundary structure and properties. fundamental processes that operate in the (Funded by EPSRC and in collaboration with Oxford phenomenon of electroepitaxy are being investigated. Instruments and University College London, and (In collaboration with Department of Metallurgy, University of Coventry*) University of Cambridge )

Fabrication of thin films of Tl-2212 Synthesis and microstructure of MgB2 Dr. H. Wu**, Dr. S. Speller, C.J. Dark, Dr. C. powders and wires Stevens*, M. Korsah, Professor C.R.M. Grovenor, Professor D. Edwards* C. Dancer, M. Hyslop, Dr. H. Wu*, Professor J. Yi***, Professor C.R.M. Grovenor, Dr. P. Kovac** Sputtering and post annealing processes are being used to deposit thin films up to 3Ó in diameter of Tl- MgB2 is a most promising new superconducting based superconducting ceramics, including films > 1 material for high current applications at temperatures micron thick for novel THz devices. The mechanisms below 30K. We are studying new methods for the of growth and the composition and microstructure of chemical synthesis of high quality MgB2 powder with the films are being investigated as a function of controlled particle size and impurity content. At the deposition parameters, and related to the same time we are collaborating with the Kovac superconducting and microwave properties. Vicinal research group in Slovakia on the analysis of the substrates are also being used to achieve off axis microstructure of high current wires fabricated with growth for specific device designs. The aim is commercial starting powder. XRD, SEM and EPMA produce optimised high Jc/low Rs materials for a wide analysis are all key aspects of the work, with high range of practical applications. (Funded by EPSRC resolution SIMS analysis of oxygen and H contents. and in collaboration with Department of Physics, (*University of Coventry, **Institute of Electrical University College London, Department of Engineering,, Slovak Academy of Sciences. Engineering Science*, Oxford, Department of ***Powder Metallurgy Research Institute, Central Metallurgy and IRC in Superconductivity, University South University, Changsha, CHINA) of Coventry**)

Page 11 Research In Progress 2004–2005

Growth of thick epitaxial films of Tl-2212 Grain boundary properties in Tl-2212 thin for novel THz device structures films M. Korsah, Dr. H. Wu*, Dr. S. Speller, C.J. Dark, Dr. S. Speller, C.J. Dark, Dr.A. Sundaresan*, Dr. Y. Professor C.R.M. Grovenor, Dr. P. Warburton** Tanaka**, Professor C.R.M. Grovenor

Superconducting films of the highly anisotropic Tl- The properties and structure of grain boundaries in Tl- 2212 phase provide a simple way of fabricating novel 2212 and Tl-1223 thin films are being studied to device structures containing a large number of correlate structure with critical current performance. precisely positioned Josephson junctions. This Both artificial and natural grain boundaries are being project is to grow Tl-2212 thin films with grown on LaAlO3 and MgO substrates, and doping of microstructures specially optimised for these devices. the boundaries to improve properties is also being Optimising epitaxial growth quality in films with attempted. The properties of these boundaries has thicknesses greater than 1 micron is the key technical been shown to fall very far from the accepted Jc/theta challange of the project, and requires a very detailed dependence found in TBCO films. (*Jawaharlal understanding of nucleation and growth processes in Nehru Centre for Advanced Scientific Research, these films. (Funded by EPSRC and in collaboration Bangalore; **Nanoelectronics Research Institute with University College London** and University of (NeRI), AIST, Tsukuba) (Funded by EPSRC) Coventry*)

II - SEMICONDUCTOR MATERIALS

Secondary electron mapping of doped Investigation of strain distributions in regions in semiconductors semiconductors Professor E. Grunbaum*, Dr. P.R. Wilshaw Dr. A.J. Wilkinson

The secondary electron (SE) signal in an SEM is used A technique for probing local elastic strain fields to produce 2-dimensional maps of doped regions in using electron back scatter diffraction patterns has silicon and III-V semiconductors. SE images of cross- been developed. The technique combines a spatial sections of doped heterostructures and laser devices resolution of ~30 nm with a strain sensitivity of 2 reveal the type and extent of doping. Quantitative parts in 10000. It is being used in conjunction with information about the observed contrast has been electron channelling contrast imaging to characterise obtained experimentally. A model has been proposed local strain and defect distributions in semiconductor and is being developed to account for the effect and materials and devices. Materials systems being new measurements are being made using energy studied include SiGe/Si, epitaxially laterally filtering of the secondary electrons. (*Dept of overgrown GaN films, device isolation structures, and Physical Electronics, Faculty of Engineering, Tel- crack tips. Aviv University, Israel.) Advanced semiconductor nanocrystals Quantum dots in optical microcavities Dr. J.M. Smith Dr. J.M. Smith, E. Tyrrell Semiconductor nanocrystals have unique optical Placing a light emitting material in an optical cavity properties that depend strongly on the crystal size, a can drastically alter its emission properties, since (i) feature that is finding applications in fields ranging photons in the cavity can only exist in certain allowed from medicine to renewable energy and information states, and (ii) the amplitude of the electric field processing. Rapid advancement in growth capabilities generated by a single photon in the cavity is very has led to exciting possibilities for further engineering large. This project takes such science to the limit of of their optical properties. I am interested in two main miniaturisation - the cavities are only micrometers in areas: producing nanocrystals that have modified size, and the emitting material is a single luminescence properties (lifetimes, linewidth); and semiconductor quantum dot. The aims are to produce understanding / controlling the influence of the an efficient 'single photon source', and ultimately to nanocrystal surface on the luminescence properties. achieve a controllable coherent interaction between By performing optical characterisation of single dot and cavity - both potentially important steps nanocrystals the underlying physics can be probed towards realisation of a quantum computer. The with the highest precision and single particle quantum cavities are also being developed for use as ultra effects can be observed. sensitive optical probes in novel forms of microscopy.

Page 12 Electronic Materials and Devices

Quantum wires and dots Room temperature light emission form Dr. J.L. Hutchison, X. Chen, Professor P.J. Dobson*, silicon Dr. G. Wakefield** D. Stowe, K. Fraser, Dr. S. Galloway*, Dr. R. Falster**, Dr. P.R. Wilshaw We are assessing methods of making semiconducting dots and wires with dimensions less than 10 nm. This Different dislocation structures produced in silicon are project is a coordinated optical, electronic and being investigated using cathodoluminescence with a structural assessment of these new materials. view to producing devices which emit at room (*Academic Director of the Oxford University temperature. The relation between impurity doping Begbroke Science Park; **Oxonica Ltd.) (Funded by and recombination is being investigated so that light EPSRC and Oxonica Ltd.) emission may be optimised. (*Gatan, UK; **MEMC, Italy) (With support from MEMC, Italy) Impurities and dislocations in Si wafers J. Murphy, C. Alpass, B. Pygall, Dr. S. Senkader, Dr. Electron field emission from dielectric films R. Falster*, Dr. P.R. Wilshaw E. Kirkby, Dr. P.R. Wilshaw

The interaction between impurities such as O, N and Experiments are being performed with a view to H and defects such as dislocations and precipitates is understanding the mechanism by which electron field being studied. In particular the diffusivity of O and N emission from flat surfaces can, in some o in the range 350-850 C is being investigated together circumstances, be improved by the deposition of a with the locking of dislocations by impurities and the thin dielectric film. Preliminary experiments are mechanism by which precipitates weaken wafers. One using, as a model system, different thickness silicon of the aims of the project is to understand impurity- dioxide films grown on silicon substrates. defect interactions so that stronger Si wafers may be manufactured. (*MEMC, Italy) (Funded by EPSRC, MEMC)

III - MAGNETIC MATERIALS

Microstructure and magnetic structure of Spin-tunnel junctions based on magnetic spin-valves and exchange-couples layered films Professor A.K. Petford-Long, Dr. H. Brown Professor A.K. Petford-Long, V Jackson, Dr. A. Kohn, Dr. T.C. Anthony*, Dr. J.A. Brug* The microstructure and magnetisation reversal mechanisms of spin-valve devices and exchange- Spin-tunnel junction devices are magnetic layered couples with applications in information storage systems which exhibit giant magnetoresistance. The technology are being studied at high spatial resolution aim is to develop these systems for applications as using electron microscopy, for correlation with their magnetic field sensors and/or magnetoresistive giant magnetoresistive properties. (In collaboration memory elements. (*Hewlett-Packard Labs.) (Funded with Seagate Technology) by Hewlett-Packard Labs. and EPSRC)

Studies of patterned magnetic thin films Composite magnetic nanoparticle systems T. Bromwich, Professor A.K. Petford-Long A. Eggeman, D. Forrest, Professor A.K. Petford- Long, Professor P.J. Dobson*, Dr. R. Potter** Thin magnetic films grown by sputter deposition and by molecular beam epitaxy are being patterned to Composite systems containing magnetic metal form arrays of magnetic antidots. Further patterning nanoparticles have many technological applications. of the films is being carried out using polymer self- The aim of this project is to fabricate these materials assembly to form arrays of magnetic dots. The using sol-gel processes, and to characterise their magnetic domain structure and magnetisation structure, composition, magnetic and transport processes are being studied by Lorentz microscopy properties. (*Academic Director of the Oxford for correlation with microstructure. The films have University Begbroke Science Park, **Johnson applications as high density storage media (Funded by Matthey) (Funded by EPSRC and Johnson Matthey) EPSRC)

Page 13 Research In Progress 2004–2005

MBE growth of epitaxial exchange-biased studied in the absence of features such as grain layers and tunnel junction structures boundaries. The magnetisation reversal of the films is being characterised using Lorentz electron C. Wang, Professor A.K. Petford-Long, Dr. R.C.C. microscopy and their microstructure is being analysed Ward* using HREM and composition mapping. The project will also include the deposition and characterisation The MBE system in the Clarendon Laboratory is of epitaxial tunnel junction structures based on a being used to grow epitaxial exchange-bias films, so variety of materials. (*Clarendon Laboratory, Oxford) that the exchange-biasing mechanism (vital to the (Funded by EPSRC) operation of modern hard-disk read-heads) can be

IV – QUANTUM INFORMATION PROCESSING

Nanoelectronics at the Quantum Edge Investigating the electronic structure of Professor G.A.D. Briggs, Dr. S.C. Benjamin, Dr. R. carbon nano-materials by STM Taylor*, Professor N.F. Johnson*, Professor D.G. D.F. Leigh, Dr. C. Norenberg, Dr. S.M. Lee, Dr. A. Pettifor, Dr. D. Hasko**, Dr. D.A. Williams***, Dr. Ardavan, Professor D.G. Pettifor, Professor G.A.D. A. Ardavan* Briggs

Oxford and Cambridge Universities are working In order to fabricate a fullerene-based quantum together with Hitachi Europe Ltd to produce radically information processing (QIP) device, we need to new devices for future computing. The project brings deposit 1-D and 2-D arrays of spin-active fullerenes together research in physics, chemistry, materials with controlled spacing onto a suitable substrate. We science and electronics engineering to make prototype are investigating small islands of various fullerenes, structures for advanced conventional computing and including C60, C70, Nd@C82, Sc@C82 and for the new field of quantum computing. Quantum Er3N@C82, on a Ag/Si(111) substrate using variable- computation is potentially the most innovative area temperature Scanning Tunneling Microscopy (STM), that can be addressed within the field of in conjunction with members of the Molecular nanotechnology, embracing nanofabrication, Modelling Laboratory who are performing density molecular nanotechnology, and atomic and molecular functional theory (DFT) calculations for these manipulation and assembly. Tremendous progress has molecules. At room temperature the fullerenes are been made in the fundamental theory of quantum mobile and diffuse across the surface to form compact information, and there is now a global race to find a islands. We observe their epitaxial relationship with practical technology for quantum computing. Our the substrate, and their preference for adsorption at initial strategy will be to develop the three most step edges, phase boundaries, and other promising solid-state nanotechnologies: a molecular inhomogeneous sites in the surface. At low approach, an all-optical approach involving self- temperatures (~77 K) the rotation of the molecules is assembled quantum dots, and a single-electron frozen out and we can to resolve the molecular approach based on nanolithography. Having orbitals of these fullerenes directly. This gives a direct determined the “winner” for quantum computing, and comparison to the calculated structures, and allows us having also evaluated the potential for revolutionary to assess the interaction between the substrate and the classical computing, we shall then focus on creating fullerenes. We will conduct further analysis on the prototype circuits. These will embody a radically new interaction between the fullerenes using Raman global addressing architecture, which enormously spectroscopy. Photoluminescence (PL) from optically reduces the number of wires and offers very active fullerenes will elucidate the possibility of significant advantages both in terms of the optical addressing of a QIP device based on these fundamental physics and in terms of the practical species. Dual evaporation experiments will be used to nanofabrication. By the end of the project we shall investigate the interactions between different fullerene have realized a small quantum circuit suitable for species. (Funded by EPSRC Foresight LINK award, subsequent development into a full quantum DTI and Hitachi Europe). computer. See www.nanotech.org for more information. (Funded by DTI Foresight LINK Award through EPSRC and Hitachi Europe Ltd )

Page 14 Electronic Materials and Devices

High fidelity operations on electron spin Logic Gates with Excitons and Spins in qubits Quantum Dots J.J.L. Morton, Dr. A. Tyryshkin**, Dr. A. Ardavan*, A. Nazir, Dr. B.W. Lovett, Dr. S.C. Benjamin, Professor S.A. Lyon**, Professor G.A.D. Briggs Professor G.A.D. Briggs, Dr. J. M. Smith, Professor J. H. Jefferson An increasing number of quantum computing implementations are turning to electron spin as the We have shown that excitons in self-assembled embodiment of a quantum bit (qubit). The ability to quantum dots are suitable candidates for use in measure and reduce systematic errors in electron spin quantum information processors. Based on this, we rotations is therefore crucial when evaluating such have proposed two methods for the ultra-fast quantum computing proposals. We have developed manipulation of coupled dot states: one exploits the pulsed electron paramagnetic resonance (EPR) optical Stark effect to entangle excitonic states of two sequences that can be used to measure precisely even adjacent quantum dots, the other uses a single small systematic errors in rotations of electron-spin delocalised exciton to generate an effective coupling qubits. Using these sequences we hope to demonstrate between spins localized on each dot. Both schemes the ability to substantially reduce these errors using may be generalized to perform arbitrary single- and composite pulse sequences, allowing high-fidelity two-qubit quantum logic gates. We now aim to apply qubit operations to be performed.(*Clarendon our formalism to optically and spin active carbon Laboratory, Oxford University; **Electrical based nanostructures, as well as to quantum dots Engineering Department, Princeton University) placed inside optical micro-cavities. (In collaboration with Hewlett Packard Laboratories Bristol and Ben- Gurion University) Endohedral Fullerenes for Quantum Information Processing Molecules inside Nanotubes: a Synergistic J.J.L. Morton, D.A. Britz, , M.A.G. Jones, Dr. K. Porfyrakis, Dr. A.M. Khlobystov*, Dr. A. Ardavan**, Host-Guest System Professor G.A.D. Briggs Dr. A.N. Khlobystov*, D.A. Britz, Dr. K. Porfyrakis, Professor G.A.D. Briggs, Dr. A. Ardavan*, Dr. J.G. One of the most remarkably robust examples of an Wiltshire*, Dr. L. Li, Dr. R.J. Nicholas unpaired electron spin within a molecule is that of a nitrogen atom trapped inside a spherical fullerene We are exploring interactions between carbon (termed N@C60). We have measured the coherence nanotubes and various organic and organometallic time of a qubit encoded within this electron spin molecules, including fullerenes. These nanostructures system and performed single qubit operations using demonstrate unique synergistic host-guest properties. pulsed electron paramagnetic resonance (EPR). We Structural and dynamic behaviour of the encapsulated are investigating the synthesis of several types of molecules is substantially affected by confinement in endohedral fullerene dimers including directly- the nanotube and is mainly controlled by geometrical bonded and oxygen-bridged dimers. These multi- parameters of the host. Complementarily, the qubit systems will then be characterised by EPR. We mechanical and electronic properties of the tubular shall study the ability to control qubit interactions host are influenced by the guest molecules due to the through the inter-fullerene bridge, and move on to coupling between the molecular orbitals of the guest investigate larger qubit arrays.(*University of and the electronic bands of the nanotube. Host-guest Nottingham; **Clarendon Laboratory, Department of systems of this type exhibit a range of functional Physics) properties which can be exploited in chemistry and nanotechnology. (*University of Nottingham; **Clarendon Laboratory, Department of Physics) Zeptolitre Reaction Vessels D.A. Britz, Dr. A.N. Khlobystov*, Dr. A. Ardavan**, Professor G.A.D. Briggs Molecular architectures templated by DNA Dr. A. Ardavan*, Dr. S.C. Benjamin, Professor We are studying chemical reactions inside single G.A.D. Briggs, Dr. R. Goodman*, Dr.A.N. walled carbon nanotubes (SWNTs). We have been Khlobystov**, Dr. J. Malo*, Dr. A. Turberfield* able to efficiently fill SWNTs with a variety of reactive molecules. These molecules can react inside We aim to establish a technology capable of using SWNTs to form a polymer of fullerene oxide with self-assembling DNA scaffolding to create functional improved topology over the bulk polymer. The use of architectures of molecular-scale components with the single-walled carbon nanotubes as reaction vessels is potential to perform computation. In our preferred recognized by the Guinness Book of World Records system quantum information will be embodied in as the smallest test-tube. (*University of Nottingham; electron spins on atoms doped within fullerene cages, **Clarendon Laboratory, Department of Physics) which are attached to a DNA lattice by covalent bonding. (Clarendon Laboratory, Department of Physics; **University of Nottingham)

Page 15 Research In Progress 2004–2005

Manufacture of HPLC Columns for Decoherence of Confined Excitonic States Separation of N@C60 Dr. B.W. Lovett, A. Nazir, Dr. S.C. Benjamin, D.A. Britz, J. Zhang, Dr. A.N. Khlobystov*, Dr. K. Professor G.A.D. Briggs Porfyrakis, Dr. A. Ardavan**, Professor G.A.D. Briggs We are investigating the primary 'decoherence' mechanisms by which quantum information is lost to N@C60 and C60 are difficult to separate, as they its surroundings from confined excitonic states. The have virtually indistinguishable affinities for most confinement might be due to a synthetic nanostructure materials. We have targeted their most apparent such as a quantum dot, or to a molecular unit, such as difference, mainly that N@C60 is more polarizable a fullerene. The decoherence is caused by interactions than C60, to facilitate separation of the two with phonons or by emission of photons. We are molecules. We are designing materials that have using a variety of methods to study these effects, exceptionally large polarizabilities and attaching them varying from simple Markovian master equations (in to silica for use as packing material for high which the environment is assumed to have no performance liquid chromatography memory), to more complex non-Markovian columns.(*University of Nottingham; **Clarendon approaches, which use the spin-boson model. We are Laboratory, Department of Physics) also looking at ways in which we can increase the coherence time of molecular devices; for example, this might be done by using tailored laser pulses to Isolation and characterization of N@C60 perform quantum manipulations, or by designing derivatives environments which do not support particles which D.A. Britz, M.A.G. Jones, J.L.L. Morton, Dr. K. interact most strongly with our quantum bits. (In Porfyrakis, Dr. Dr. A. Ardavan*, Professor G.A.D. collaboration with Hewlett Packard Laboratories Briggs Bristol and Ben-Gurion University)

We have recently succeeded in adding useful ESR Study of Carbon Nanostructures for functional groups to N@C60 and separating the Quantum Computing material purity approaching 100%. These functional groups alter the spin properties of the molecule and G. Morley, Dr. A. Ardavan*, Professor G.A.D. Briggs may change important parameters for its use as a computational quantum bit. We find that certain Molecules of N@C60 have an exceptionally sharp functional groups do not have a substantial effect on ESR signalÊcorresponding to long-lived electronic these properties and thus still useful for quantum spin states. The suitability of theseÊstates for storing computation. The subtle changes imposed by the quantum information is being evaluated. A chain of functional groups need to be further studied to interacting spin-active molecules may be realised by determine the extent of their effect.(*Clarendon filling a carbon nanotube. The possibility of using Laboratory, Department of Physics) such a chain for processing quantum information is being considered. See www.nanotech.org (*Department of Physics) (Funded by EPSRC Foresight LINK Project, DTI and Hitachi Europe).

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Page 16 Processing

D. Processing

Nodal optimisation in truss structures Modelling, microstructure and properties of Ms S. Panteny, Professor P.S. Grant nickel superalloys processed by centrifugal spray deposition Multi-material high stiffness, low weight 3D truss Dr. Z. Shi, Professor P.S. Grant, Dr. M. Ward* structures made from node and strut assemblies promise great benefits in structural engineering. The main scientific objective is to underpin the Truss structures can be used as the building blocks for commercial and technological development of the lower weight wing structures, enabling longer wings Centrifugal Spray Deposition (CSD) process through to be manufactured, while their excellent vibration improved scientific understanding. This will be resistance, high damage tolerance, and incorporation achieved through the application of state of the art of stealthy materials makes them ideal for unmanned diagnostic techniques, systematic experimentation and air vehicles (UAVs). Currently, truss structures have the development of process models which better achieved only limited applications as the define the relationships between atomisation and underpinning joining technology has yet to be deposition parameters, preform shape, microstructure developed and therefore potential weight savings and and properties. Technical objectives are the spray manufacturing costs have failed to meet expectations. forming of high performance Ni alloys (including This project is investigating innovations required to IN718, Waspalloy and the Rolls Royce alloy RS5); enable the wider implementation of truss structures in the identification of deposition strategies consistent civil applications by: ¥ the manufacture of lightweight with the production of axi-symmetric components demonstrators defined by end-users; ¥ the with extended axial length; and the production of investigation of enabling joining technologies; ¥ the medium-large diameter ring-shaped preforms with development of design and simulation software for internal and external shape. The programme aims to complex 3D truss geometries; ¥ the investigation of provide, through innovative developments in new node materials and their assemblies into truss materials processing, modelling and optimisation, an structures; and ¥ the development of joining alternative high yield, cost-effective manufacturing technologies for repair. The project involves two route for the production of seamless ring and casing universities, a research and technology organisation components for use in aeroengine, industrial and and five industrial partners. (Funded by Advanced marine gas turbines (In collaboration with Composites Group, Airbus UK, Carr Reinforcements, *Birmingham University and funded by EPSRC, Crompton Technology, MIRA, Ellis Developments, DSTL, Qinetiq, Doncasters Ltd, Alstom, Bodycote Oxford Brookes University, DTI.) HIP Ltd, Rolls-Royce plc).

Reliable compact capacitors for aerospace Advanced materials for plasma facing applications components (PFC) in fusion devices C. Hinchliffe, Dr. T. Starke, Dr. C. Johnston, G. Thomas, Professor P.S. Grant Professor P.S. Grant, Professor P. Dobson* This project concerns the use of thermal spraying and Current capacitor technology significantly limits the other manufacturing techniques to produce thick temperature capability and electrical performance of coatings with through thickness variations in power electronics relative to the "More Electric compositions that are optimised for service in first Airframe" systems requirements, which are emerging wall applications in fusion reactors. Tasks include rapidly as a key priority for both aeroengine and evaluation of possible materials combinations for airframe manufacturers. Novel capacitor materials plasma facing components from the perspective of all combining high dielectric ceramics and high major contraints due to plasma surface interactions, performance polymers are being developed for aero- physical properties for heat removal, radiation engine applications, particularly within the more damage, etc. Evaluation PFC materials will be electric aircraft concept. Investigations include manufactured in-house using processing strategies for characterisation of the fundamental material thermal and stress control, and optimised adhesion, properties using advanced analytical instruments, minimimum porosity and surface roughness, etc. clean room characterisation of the electrical Some material combinations are novel and offer properties, development of fabrication routes, and particular challenges for processing technologies. modelling of behaviour for lifetime prediction. (Funded by UKAEA) (Funded by Rolls-Royce plc and EPSRC) (*Academic Director of the Oxford University Begbroke Science Park,)

Page 17 Research In Progress 2004–2005

Direct chill casting of Al alloys Spray formed Al-Li-Mg-Zr(Sc) alloys alloys Dr. K.A.Q. O’Reilly for airframe applications Dr. S. Hogg, L. Thomas, Dr. I.G. Palmer, Professor A one tonne direct chill (DC) caster has been installed P.S. Grant in the department and is being used to investigate the effects of alloy composition, processing parameters A state-of-the-art 80kg Al spray forming plant has and grain refinement practice on the microstructures been installed and commissioned in a dedicated and properties of Al alloys. (Funded by JIF in laboratory. Research focuses on production and collaboration with Luxfer Group) evaluation of low density Al-Mg-Li-Zr(Sc) alloys by spraycasting; characterisation of microstructure; investigation of secondary processing on the Rapid spray formed tooling development of the microstructure and the resulting T. Rayment, Dr. S. Duncan*, Professor P.S. Grant mechanical properties; definition of new compositions and processing conditions for optimised alloys; and Electric arc spraying of liquid steel droplets onto scale-up to billet sizes suitable for forging and shaped substrates is being investigated for the rapid component trials. (Funded by EPSRC, Joint manufacture of dies for stamping/pressing tools for a Infrastructure Fund and BAE Systems and in wide range of applications. Lead times are several collaboration with Southampton University, Imperial times faster than for conventionally machined dies College, BAE Systems and QinetiQ). and tooling. Research focuses on closed loop feedback control of residual stresses, simulation of shape evolution and microstructural characterisation. Rheocasting of Al alloys (*Department of Engineering Science) (Funded by S.B. Park, Dr. I.C. Stone, Professor B. Cantor* EPSRC, Sulzer Metco and Ford Motor Co.) The recently developed slurry-on-demand UBE New Rheocasting process is being investigated. Slurries are DC and shape casting of wrought Al alloys being produced on a commercial UBE Rheocaster, I. Davidson, Dr. K.A.Q. O’Reilly, Dr. I.C. Stone, Dr. and their microstructures are being characterized M.R. Jarrett* quantitatively in order to investigate the role of the individual process parameters on the morphology and Control of intermetallic phase selection, via grain scale of the primary Al phase. The mechanical refinement procedures and minor element additions, is properties of the slurries are being measured using being investigated in D.C cast, squeeze cast and semi- thermal mechanical analysis (TMA) in order to solid processed conventionally wrought Al correlate slurry microstructure with properties and alloys.(*Alcoa) (Funded by Faraday Partnership and castability. The results are being used to determine Alcoa) constitutive laws for semi-solid alloys. (*University of York) Carbon fibre reinforced magnesium M. Russell-Stevens, Dr. R.I. Todd, P. Schultz* Optimisation of spray forming of advanced high quality components of Ni super alloys Microstructural, residual stress and mechanical for aeronautic applications properties of long fibre carbon fibre reinforced Dr. J. Mi, Dr. I.C. Stone, Professor P.S. Grant magnesium alloys manufactured by squeeze casting are being investigated.(*Leichtmetall The mechanism of refined, equiaxed grain evolution Kompetenzzentrum Ranshofen) (Funded by EPSRC) in spray forming, and the role of insoluble nitride, carbides and microporosity, are being investigated by Squeeze casting and semi-solid processing a combination of manufacture of Ni preforms by of Al alloys spray forming under different processing conditions and microstructural characterisation by EPMA and Dr. I.C. Stone, Dr. K.A.Q. O’Reilly phase extraction/XRD. The development of Ni superalloys which exploit the unusual solidification An UBE 350 tonne squeeze casting and semi-solid conditions in spray forming is also being explored in processing machine is has been installed in the order to enhance high temperature strength and creep department and will be used to investigate the effects properties (Funded by EU Framework V and in of alloy composition, and processing parameters on collaboration with Bremen University, ITP, the microstructures and properties of squeeze cast and Turbomeca, BEG, MTU, BSTG, ALD, Inasmet) semi-solid processed Al alloys.

Page 18 Processing

The role of secondary intermetallic phase Melt conditioning of Al alloys selection on hot tearing of aluminium M. Lovis, Dr. K.A.Q. O'Reilly, Dr. I.C. Stone, P.G. alloys Enright* L. Colley, Dr. I.C. Stone, Dr. K.A.Q. O’Reilly This project is developing novel thermal and chemical Many Al alloys suffer from hot tearing (cracking) melt conditioning procedures for the control of during casting due to high thermal stresses developed microstructures during casting, providing evaluation during solidification. The type, size and morphology and measurement technologies for the same, and will of intermetallics formed during the final stages of demonstrating the benefits of melt conditioning on (i) solidification can affect hot tearing and that correct the manufacture of thin walled, high integrity manipulation may lead to reduced hot tearing automotive sand and die castings; and (ii) the tendency. In this project, the morphology of the ‡-Al selection of preferred intermetallic phases during DC dendritic structure and the selection of secondary Al- casting. (*N-Tec Limited) (Funded by TCS and N- Fe-Si phase intermetallics of an aluminium alloy are Tec Limited) being controlled, and their influence on the mechanical properties of the alloy at very low solid Sedimentation studies in Al alloys fraction are being measured. (Funded by EPSRC) S. Srimanosaowapak, Dr. K.A.Q. O'Reilly, Professor J.D. Hunt Spray formed silicon-aluminium alloys for electronic packaging applications Sedimentation studies are being developed to (i) investigate the effects of impurities, grain refiners and A. Lambourne, Professor P.S. Grant melt cleanliness on heterogeneous nucleation in commercially relevant Al alloys; and (ii) remove Alloys containing up to 70wt%Si are being impurities and inclusions from melts in order to manufactured by spray forming. These alloys offer a improve melt cleanliness. (Supported by the Royal unique combination of low thermal expansion, high Thai Government) thermal conductivity and low density, and are investigation for electronic package thermal management applications in the avionics, satellite and Manufacture and characterisation of nano- other industries. The research concerns the quasicrystalline aluminium alloys characterisation of the key mechanical and microstructural properties of Al-70Si; the M. Galano, Dr. F. Audebert*, Dr. I.C. Stone, optimisation of spray forming; and to enhance alloy Professor B. Cantor** properties by ternary alloy additions. (In collaboration with Sandvik-Osprey). Al-base nanocomposite materials containing high volume fractions of quasicrystalline dispersoids are being produced by rapid solidification techniques. Control of temperature during vacuum Particular emphasis is being placed on the dependence plasma spraying of alloy composition on the ability to form the quasicrystalline phase during quenching. This project Professor P.S. Grant, E. Davies*, Dr. S. Duncan* is partly within the framework of an EU Research Training Network with 9 European partners Vacuum plasma spraying (VPS) is the injection of (www.materials.ox.ac.uk/nano-al) (*University of metal or ceramic powder (10-50microns) into a hot Buenos Aires; **University of York) (Funded by EU gas plasma that melts and projects the molten droplets and British Embassy Korea S&T Fund) at high velocity onto a substrate to form a coating or composite. In order to maintain the uniformity and material properties of the coating, it is important to Melt cleanliness in direct chill (DC) casting regulate the temperature of the surface during the of 6xxx series aluminium alloys spraying process. This project concerns the measurement of the temperature of the coatings A.C.M. Lui, Dr. I.C. Stone, Dr. K.A.Q. O’Reilly surface using pyrometry and infrared thermal imaging and the use of data to adjust the VPS process in real- Due to the presence of Fe and Si as impurities, Al-Fe- time to control the required temperature. (In Si intermetallic phases form during DC casting of collaboration with *Department of Engineering wrought Al alloys and have a marked effect on down Science and funded by EPSRC). stream formability by processes such as extrusion. Oxide films and inclusions entrained in molten Al alloys can influence the nucleation of these secondary intermetallics. Using techniques for the control and measurement of melt cleanliness, the aim of this project is to understand the role of oxide inclusions on secondary intermetallic phase selection.

Page 19 Research In Progress 2004–2005

The Effect of grain refiner poisoning on intermetallic selection in 6xxx series Al alloys A.C.M. Lui, Dr. K.A.Q. O'Reilly, Dr. I.C. Stone

In addition to their grain refining effect, commercial titanium diboride based grain refiners can also affect the selection of Al-Fe-Si intermetallic phases during solidification of Al alloys. Additions of Zr or other certain other elements can poison the grain refining effect. This project aims to answer the question of whether such elements also poison the effect that grain refiners have on intermetallic selection.

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Page 20 Phase Transformations, Surface and Interfaces

E. Phase Transformations, Surfaces and Interfaces

I - PHASE TRANSFORMATIONS

The structure and evolution of copper-rich TEM studies of radiation damage in precipitates in ferritic steels and their role materials for fusion reactors in hardening Dr. M.L. Jenkins, Dr. S.G. Roberts, A. Pilcher- Dr. M.L. Jenkins, Professor J.M. Titchmarsh, Dr. S. Clayton Lozano-Perez Materials issues will be crucial to the success of Hardening due to formation of copper precipitates is a future fusion reactors. Structural materials will o major problem for in-service performance of reactor- operate at temperatures up to 600 C, will need to pressure-vessel steels. The project aims to answers withstand stresses up to 300MPa, and will accumulate the following questions: over their lifetime radiation damage from fast neutrons amounting to ~100 displacements per atom, 1. How do precipitate nucleation and growth, combined with high levels of helium and hydrogen structure and composition depend on irradiation and produced in transmutation reactions. It is essential thermal conditions? that any material used maintains adequate strength 2. What are the mechanisms of copper transport? and toughness, while suffering minimal dimensional changes through swelling and creep. 3. What is the effect of bcc-9R transformation on the copper-precipitate binding energy and overall Candidate materials include steels based on iron ~9% kinetics? chromium, vanadium alloys and tungsten. This project uses advanced techniques in electron microscopy to 4. What is the hardening mechanism of the coherent characterise the development of radiation damage in bcc precipitates? these materials. (Funded and in collaboration with 5. Do dislocations cut through bcc precipitates, EURATOM/UKAEA) leaving them essentially unchanged, or do they induce transformation to the 9R structure? Cyclic phase transformations 6. What is the hardening mechanism of the incoherent I. de Ardo, Dr. K.A.Q. O'Reilly, Professor B. Cantor* 9R precipitates? 7. How are the mechanisms influenced by The effect of temperature cycling is being incorporation of other alloying elements? investigated on the melting, solidification and solid state phase transformations in pure metals, alloys and (In collaboration with University of Liverpool and amorphous materials using a novel calorimetric Univerity of Illanois) technique and TEM to determine kinetics of phase (Funded by EPSRC, Rolls-Royce and INSS) transformations. (*University of York)

Atomic scale studies of solute distributions One-dimensional crystal growth inside at grain boundaries and interphase single-wall carbon nanotubes interfaces Dr. J.L. Hutchison, Dr. J. Sloan, Dr. A.I.Kirkland, R. Carter, A. Vlandas Professor M.L.H. Green* Dr. H. Zurob, Dr. A. Schneider*, Professor A. Cerezo, Professor G.D.W. Smith Crystals of various salts and metals grown within single-wall carbon nanotubes are effectively 1-D The objective of this work is to understand how solute wires, with a range of interesting physical properties segregation to interfaces inhibits grain boundary which arise from their unique configurations, We are migration and affects the kinetics of solid-state phase exploring ways of growing these structures, which are transformations. Atomic-scale analysis of solute characterised by HREM, EDX and EELS. Their segregation in the 3-dimensional atom probe will be physical properties are also under investigation. combined with computer modelling using (*Inorganic Chemistry Laboratory) (Funded by ThermoCalc/DICTRA. (*Max-Planck-Institut fur EPSRC, Leverhulme Trust and The Royal Society) Eisenforschung, Dusseldorf.)

Page 21 Research In Progress 2004–2005

II - OXIDATION AND CORROSION

The study of thick corrosion layers on Ageing of organically coated metal surfaces archaeological metals using controlled E. Whyte, Dr. J.M. Sykes, Dr. H.E. Assender, laser ablation in conjunction with an Professor G.A.D. Briggs external beam microprobe The project brings together experimental and M.H. Abraham, Dr. G.W. Grime*, Dr. J. P. Northover predictive modelling approaches to the investigation of the degradation, or ageing, of polymer coatings The variation with depth of the composition of applied to metal substrates. The project will combine corrosion layers on buried metal objects can provide data from electrochemical (EIS, scanning Kelvin the archaeologist with valuable information relating to Probe) experiments with physical and chemical the burial conditions of the object. In some cases these information from acoustic microscopy, scanning layers can be very thick (up to 1mm) and so normally, probe techniques and surface chemical analysis in destructive methods such as sectioning are used to order to determine the key factors involved in the characterise the layers. The technique developed here degradation of coating systems. (In collaboration with uses a micro-focused high power pulsed Nd:YAG Corus)(Funded by EPSRC and Corus) laser to ablate the corrosion layer in a series of controlled steps, while monitoring the composition of the exposed surface using PIXE and RBS in the The origin of corrosion in coated metal external beam facility of the Oxford Scanning Proton packaging containers Microprobe. The region of the surface removed by the laser beam is typically less than 500mm diameter and G. Chadd, Dr. J.M. Sykes so, by comparison with other sampling techniques, the effect on the appearance of an object is Acoustic microscopy, scanning Kelvin probe and AC minimal.(*University of Surrey) impedance are being used to investigate factors influencing corrosion in coated tinplate and other metal containers. (In collaboration with Crown Technology.)

III - SURFACE REACTIONS AND CATALYSIS

Controlled atmosphere analytical electron Catalytic atom probe microscopy P. Bagot, Professor G.D.W. Smith, Professor A. Dr. J.L. Hutchison, Dr. A.I. Kirkland Cerezo, T.J. Godfrey, Dr. T. Visart*, Professor N. Kruse* A 400 kilovolt analytical transmission electron microscope has been extensively modified and A specially adapted atom probe, incorporating a gas equipped with special controlled-atmosphere reaction cell, has been developed in order to permit specimen stage. A number of projects of chemical and the atomic scale study of catalytic reaction processes. materials interest are now being undertaken, e.g. the (*Free University of Brussels.) (Funded by EPSRC, study of catalysts under their working environments. in collaboration with Johnson Matthey. )

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Page 22 Characterisation

F. Characterisation

I - SCANNING TUNNELLING AND ATOMIC FORCE MICROSCOPY

Growth and characterization of nitride The surface structure of SrTiO3 (001) semiconductor nanostructures reconstructions Professor G.A.D. Briggs, Dr. M.R. Castell, Dr. C. D.T. Newell, Dr. F. Silly, Dr. M.R. Castell Norenberg, Professor A.P. Sutton Ever increasing miniaturisation of integrated circuit The growth and properties of epitaxial nitride technology continues to be a critical capability for the semiconductor nanostructures are studied, with a view microelectronics industry in order to increase to discovering materials systems that may be useful functionality and fuel market expansion. One of the for quantum structures. Islands are grown in our major challenges identified by the International variable temperature STM, and examined in situ. We Technology Roadmap for Semiconductors (ITRS) is investigate factors that affect their shape and size the introduction of new materials into the distributions, the phases that are present, and the manufacturing process. Within a 5 year timeframe surface structures and electronic properties. Atomistic there is a good prospect of replacing the materials of and multiscale modelling enables the structure of the current SiO2 transistor gate insulator in surfaces and interfaces to be elucidated, and the complementary metal oxide semiconductor (CMOS) distribution of island types and sizes to be accounted devices. One of the major contenders for the material for. (Funded by The Royal Society) replacement is SrTiO3. The purpose of the project is to investigate the surface reconstructions of SrTiO3 and determine their influence on the growth of silicon Atomic structure of oxide surfaces on these surfaces. Atomic resolution imaging through Dr. M.R. Castell, Dr. A.T. Paxton*, Dr. C.F. scanning tunnelling microscopy (STM) is the main McConville** research tool. This work is sponsored by EPSRC and Oxford Applied Research. Through the combined use of scanning tunnelling microscopy, atomistic simulations, and ion scattering spectroscopy, the atomic surface structure of New force microscopy techniques in reconstructed perovskite surfaces is being studied. ambient (*Queens University Belfast, **University of C. Ramanujan, Professor J.B. Pethica* Warwick) (Funded by The Royal Society) A new, high resolution AFM which functions in liquids has been developed. We have successfully Systematic control of the size and shape of observed normal and lateral stiffness fluctuations due epitaxial quantum nitride nanostructures to individual molecular layering. The unusual shear Dr. C. Norenberg, Dr. R.A. Oliver*, Dr. V. properties of the final liquid molecular layers adjacent Lebedev**, Dr. M.R. Castell, Professor G.A.D. to a solid are being studied. (*Trinity College, Dublin) Briggs

The growth of self-assembled quantum nitride AFM of aqueous bio-systems nanostructures (InGaN, AlGaN) by molecular beam C. Ramanujan, Professor A.B. Watts*, Professor J.B. epitaxy (MBE) is studied in-situ by elevated- Pethica** temperature scanning tunnelling microscopy (STM) and electron diffraction to investigate nucleation and We have recently used a new AFM to resolve the elucidate growth modes. The size and shape solvation layers in water. The low amplitude AFM distributions of quantum dots are studied to develop a technique is now being applied to image the structure nanostructure diagram as a function of composition near peptides inserted at low density in lipid layers. and growth parameters. (*Cambridge University, (*Dept. of Biochemistry; **Trinity College, Dublin) Department of Materials, **TU-Ilmenau, Germany)(Funded by The Royal Society)

Page 23 Research In Progress 2004–2005

STM of polar SrTiO3 reconstructions Nanostructures on the SrTiO3 (001) B. Russell, Dr. F. Silly, Dr. M.R. Castell Surface D.S. Deak, Dr. F. Silly, Dr. M.R. Castell There are certain surfaces of crystalline materials that cannot have bulk-like terminations because this would Atomically resolved scanning tunnelling microscopy lead to an infinite surface dipole. These surfaces are of the SrTiO3 (001) surface reveals that certain called polar surfaces and the atoms on a polar surface treatments give rise to two types of self assembled undergo substantial surface reconstructions in order to nanostructures. The one dimensional structure type eliminate the dipole. The aim of this project is to consists of perfectly straight lines that run in <100> study at atomic resolution the reconstructions of the directions and have a minimum separation of 2.4 nm. SrTiO3 (111) and SrTiO3 (110) and related surfaces. The other structures are dots that on closest packing Scanning tunnelling microscopy and electron form 2.4 nm x 1.6 nm arrays. It is proposed that both diffraction will be used to determine the surface structure types are formed through nano-crystalline structure, and Auger electron spectroscopy and growth of non perovskite phases on the surface. secondary ion mass spectroscopy will reveal the Further structural characterization and spectroscopy chemical composition. (Sponsored by EPSRC.) on these surfaces is currently being carried out. (Funded by The Royal Society and EPSRC) Structure and electronic properties of titanate materials using TEM and STM Atomic-scale studies on the growth of H. Marsh, Dr. M.R. Castell, Dr. A.I. Kirkland metals on GaN(0001) Dr. C. Norenberg, Dr. R.A. Oliver* Complex metal titanates exhibit a variety of unusual structural, surface and electronic properties. This In the past ten years, gallium nitride technology and project aims to carry out high resolution studies on a its device applications have been developed rapidely. variety of doped titanate systems such as Nb doped The performance of these devices (e.g. LEDs, laser diodes and high-power transistors) relies on good SrTiO3 where we expect phase separation to occur at high dopant concentrations. By combining state of the metal-GaN contacts. This project is focused on art scanning probe and transmission electron atomic-scale studies on the growth of metals (Pt, Pd, microscopic techniques it will be possible to correlate Au, Ti) on the GaN(0001) surface using variable electronic and structural properties of these materials temperature scanning tunnelling microscopy in with atomic scale resolution. combination with spectroscopic techniques. Fundamental issues such as adsorption mechanism, wetting behaviour, growth modes and the influence of Growth and spectroscopy of metallic surface treatments are investigated. (*Dept. of nanoislands Materials, Cambridge University)(Funded by The Royal Society) Dr. F. Silly, Dr. D. Imeson*, Dr. M.R. Castell

Nanometre sized metal islands on oxide supports are used in diverse applications from catalytic materials to gas sensors. Interaction between the oxide support and the islands, the island shape, the temperature dependence of island ripening, and molecular interactions with the islands are all active areas of study. The atomic structure of the islands are imaged with scanning tunnelling microscopy, and a variety of spectroscopic techniques are used to measure their electronic structure. (*DSTL)

Page 24 Characterisation

II - FIELD-ION MICROSCOPY AND ATOM PROBE MICROANALYSIS

Scanning atom probe Early stages of precipitation in 6XXX N. Grennan-Heaven, T.J. Godfrey, Professor A. automotive sheet Cerezo, Professor A.PK. Petford-Long, Professor M. Zandbergen, Professor A. Cerezo, Professor G.D.W. Smith G.D.W. Smith

The requirement of a sharp needle specimen can limit The thermal response of 6XXX series aluminium the type of materials that can be analysed in the atom sheet materials, as used in the automotive industry, is probe, and is especially problematic in the area of thin very sensitive to time at room temperature prior to films. We are testing a new type of atom probe ageing during the paint-bake process. The system, first proposed by Nishikawa (Kanazawa, compositional variations during the early stages of Japan) in 1993, which uses a micron-sized extraction clustering and precipitation are being studied on the electrode to allow analysis of microtips formed in thin atomic scale using three dimensional atom probe film materials. This new instrument will allow microanalysis. (Funded by the Netherlands Institute atomic-scale microanalysis of electronic materials and for Metals Research.) layered metallic films. (Funded by EPSRC, DTI and Oxford Nanoscience Ltd., and in collaboration with Hitachi Global Storage Technologies) Thermal ageing of steels Dr. G. Sha, C. Zhu, A. Morley, Professor A. Cerezo, Atom probe analysis of information storage Professor G.D.W. Smith materials The atomic-scale changes which take place in the S. Pinitsoontorn, Professor A. Cerezo, Professor A.K. microstructure and composition of pressure vessel Petford-Long, Dr. D.J. Larson* steels during long term thermal ageing are being investigated by three-dimensional atom probe Thin metallic layered films with applications in techniques. (Funded by Rolls Royce and EPSRC.) information storage are being grown by sputter deposition and atom probe tips are being fabricated from these layers by FIB milling. The layer Studies of advanced electronic materials composition and interface nature are being studied with a pulsed laser 3-dimensional atom using both three-dimensional atom probe analysis, in probe parallel with HREM studies of the crystal structure of Professor A. Cerezo, Professor G.D.W. Smith the films. Experimental analysis of interface changes with thermal annealing is being compared with Whilst the 3-dimensional atom probe technique is simulations of the interdiffusion process. (*Seagate widely used for studying metallic alloys, the use of a Technology) high voltage pulse to remove atoms from the specimen surface limits the application of the 3D Reconstruction of atom probe data technique in the area of semiconductors and highly resistive materials. However, laser pulsing can be Dr. G. Chapman*, Dr. P.J. Warren, Professor A. used to overcome this problem. This project will Cerezo investigate the use of laser pulsing in the 3D atom probe and its effect on the range of materials that can Software for accurate 3-D reconstruction of data from be analysed and the quantitativity of the results the position-sensitive atom probe (PoSAP) is under obtained. The instrument will be used to study continuous development. Algorithms include specific problems in advanced electronic materials statistical functions for the detection of the early and devices, with materials being provided by a stages of clustering in alloys, and the use of Fourier number of industrial collaborators. (Funded by transforms to permit detailed crystallographic Oxford nanoScience.) reconstruction. (Funded by *Oxford Nanoscience Ltd.)

Page 25 Research In Progress 2004–2005

III - ELECTRON DIFFRACTION AND TRANSMISSION MICROSCOPY, SCANNING ELECTRON MICROSCOPY, X- RAY MICROSCOPY AND MICROANALYSIS

The Department has a comprehensive range of electron optical instruments for structural and chemical characterization on the atomic level. In addition to a number of routine transmission and scanning electron microscopes, there are several state-of-the-art instruments for:

High resolution electron microscopy (HREM) The Department’s 400 kilovolt JEOL 4000EX(II) eletron microscope, commissioned in 1989, has a point-to- point resolution of 0.16nm with an information limit approaching 0.12nm; this is currently better than any other instrument in the UK. The technique of structure imaging is being used to elucidate disorder on the atomic scale in a wide range of variety of crystalline materials. This instrument is equipped with parallel EELS (electron energy-loss spectroscopy) and an on-line TV system.

Analytical electron microscopy (AEM) A Philips CM20, a modern 200 kV AEM with full analytical facilities, was installed in 1990. A unique feature of this instrument is an energy-dispersive X-ray system (EDX) with simultaneously usable twin detectors. One detector is a standard thin Be window type, capable of quantitative analysis of elements down to Na (Z=11). The other is a windowless detector capable of analysing for light elements down to B (Z=5).

Field-emission-gun high resolution electron microscopy (FEG-TEM) Early in 1999 the Department installed and commissioned the UK’s first 300 kilovolt field-emission-gun high resolution electron microscope. This instrument, a JEOL 3000F, is fully equiped with a comprehensive range of advanced analytical facilities, including light-element sensitivity EDX, parallel electron energy loss spectroscopy (PEELS), energy-filtered imaging (GIF), an electrostatic biprism for electron holography, a high performance CCD camera and a piezoelectric, drift correcting specimen stage. With a capability of microanalysis and electron diffraction from areas down to <0.4nm in diameter, and a spatial resolution of 0.16nm, this instrument is being used in a wide range of applications, involving new nanostructured materials. Recent upgrade includes STEM and High-angle Annular Dark Field imaging.

Aberration-corrected electron microscopy As part of the Departmental JIF grant, the Department recently commissioned the world’s first electron microscope to incorporate two aberration correctors, in both the image-forming and probe-forming lenses. This microscope is installed in a specially built suite of rooms at the Begbroke site. Based on a JEOL 2200FS it extends our high resolution imaging capability to the 0.1 nm level, and also enables us to carry out nano-scale analysis at the same level. The unique instrument also has an in-column electron energy filter (omega-type), an X-ray detector, and is fully equipped with high performance digital image recording.

In-situ high resolution analytical electron microscopy A 400 kV high resolution electron microscope (JEOL 4000EX) has been extensively modified so that it can be equipped with either a gas environmental cell for in-situ studies under controlled atmosphere conditions, or with a low-field objective pole-piece for studies of magnetic materials. The unique gas environmental cell facility is capable of better than 0.3nm resolution whilst the specimen is surrounded by gas and held at elevated temperature. The instrument also includes x-ray microanalytical and electron energy loss spectroscopic (PEELS) facilities, together with an on-line TV imaging and recording system. With the low-field objective pole-piece inserted magnetic specimens can be studied under a controlled applied field or at elevated temperatures. Recent additions to the instrumentation enable magnetisation configurations to be mapped quantitatively.

Scanning electron microscopy (SEM) The JEOL JSM-840F field emission scanning electron microscope (FEG-SEM) was installed for the purpose of obtaining images of crystal defects in bulk materials using the electron channelling contrast imaging (ECCI)

Page 26 Characterisation technique developed in the department. This machine can produce both images of single dislocations and electron channelling patterns (ECP) and is being used to investigate sub-surface dislocation arrays and networks in partially relaxed epilayer materials and also to study defect distributions around crack tips. A JEOL JSM- 6300 scanning electron microscope has also been installed for electron diffraction experiments. This has a LaB6 gun which gives a higher beam current but also a larger probe size. An electron back scatter diffraction (EBSD) system allows automated mapping of local crystal orientation.

Remote scanning electron microscopy (WebSEM) A JEOL 5510LV was installed at Begbroke in 2003, and is extensively used for the development of remote microscopy in collaboration with the Oxford University e-Science centre. It has a LaB6 electron gun and operates between 0.5 and 30 kV. Using secondary electron imaging, the best resolution attainable on high contrast samples (Au on C) is 3.5 nm at 30 kV in high vacuum mode and 4.5nm in low vacuum mode. Facilities available on this instrument include: Conventional secondary electron imaging of surface topography in high vacuum mode; back scattered electron imaging with annular detector, for compositional contrast and channelling contrast imaging in high vacuum mode; direct digital image capture to PC; remote internet control; low vacuum mode with back scattered electron imaging allowing observation of samples in a variety of gas environments at pressures from 1-270 Pa.

High resolution scanning electron microscopy The new field-emission gun, scanning electron microscope (JEOL 6500F) is installed at Begbroke and has been configured to perform a wide range of materials characterisation. High resolution imaging can be obtained using an EHT range of 1-25 keV (5nm-1nm) and it is particularly useful for imaging uncoated, non-conducting samples such as polymers and ceramics. It is interfaced to energy dispersive x-ray analysis, cathodoluminescent spectroscopy and electron back-scattered diffraction ancillary equipment for specialised investigations

Electron probe microanalysis (EPMA) The department made a successful joint proposal with Department of Earth Sciences to the 1997 Joint Research Equipment Initiative for a high-specification microprobe. The instrument chosen was a JXA 8800RL electron probe microanalyser with four wavelength-dispersive X-ray spectrometers, for high-volume, automated microchemical measurements. This instrument is particularly suitable for light element analysis and X-ray mapping. It was installed in October 1999. The microprobe will contribute essential microchemical information to a series of research projects investigating metallic, ceramic, composite, superconducting, biomedical and sedimentary materials. The overall objective of the research is to apply state-of-the-art microprobe techniques in an integrated way to synthetic and natural materials. The scientific and technological impact will range from the development of improved efficiency aeroengine components and new prosthetic bone implants to phases synthesised at ultra-high (earth’s core) pressures and marine sediments related to global change and the environment.

Focused Ion Beam system (FIB) The department has recently installed an FEI FIB2000 TEM system that is being used for micromachining with a spatial resolution down to 12 nm, and for sample preparation of TEM and atom-probe samples from specific sites. The system includes gas injectors for enhanced etching of metals and insulators, plus deposition of Pt.

Secondary Ion Mass Spectrometry (NanoSIMS)) A Cameca NanoSIMS50 has recently been installed as part of the Departmental JIF grant. This instrument is a state-of-the-art Secondary Ion Mass Spectrometry facility with exceptional lateral spatial resolution (100 nm) and with the excellent chemical sensitivity characteristic of the dynamic SIMS technique. The NanoSIMS is to be applied to a wide range of problems in materials science (grain boundary and interface analysis, trace light element analysis in Ni and Al alloys (including a unique ability to perform precise H mapping), diffusion mechanisms in polymer blends and 3-D dopant mapping in semiconductor materials and devices. In addition, we will develop new collaborations in the chemical analysis of biological materials with colleagues in Oxford and elsewhere - the first of these will be on the study of metal species in hyperaccumulator plants, and in the mapping of radiopharmeceuticals in human tissue samples.

Page 27 Research In Progress 2004–2005

Nanometer scale induced structure between In-situ TEM studies of magnetic domain amorphous layers and crystalline materials structure Professor D.J.H. Cockayne, Professor A.P. Sutton, Professor A.K. Petford-Long, R.C. Doole Dr. C. Marsh, Dr. M. Doblinger, Dr. G. Winkelman, Dr. C. Dwyer, Dr. C.M. Bishop+, Professor M. Facilities are being developed for Lorentz microscopy Ruhle*, Professor M. Hoffmann**, Dr. M. Gautier- of magnetic materials using a 400kV TEM. Facilities Soyer***, Professor C. Carter +, Professor Y-M. developed so far allow the effects of temperature and Chiang, Professor R. French, Professor Garofalini applied fields on the magnetic domain structure to be +++, Professor W-Y. Ching , Dr. R. Cannon studied in situ using heating, cooling and magnetising stages, with the additional capability of observing Interfaces between amorphous/glassy layers and active magnetoresistive elements in situ. The range of crystalline materials are playing an increasingly facilities is being further extended. important role in the properties of manufactured ceramics and composites, especially as they move towards the nanometre scale. The goal of this project Structure of amorphous materials is to achieve a complete computational and Professor D.J.H. Cockayne, C. Lang, A. Duggan, Dr. experimental description of the structure and basic D. Nguyen Manh* properties of crystal/glass interfaces, for the purpose of improving materials properties. This project is a Techniques for investigating the structure of joint project funded by EU and NSF between amorphous thin films and small volumes of participants at *Max Plank Institute, Stuttgart, amorphous materials have been developed and are **University of Karlsruhe, ***CEA, Saclay, +MIT, being widely applied to obtain the radial distribution ++University of Pennsylvania, +++Rutgers function. These techniques are accurate for single University, University of Missouri-Kansas; and element materials, but require further development in Lawrence Berkeley Lab, San Francisco. the case of alloys. In this project, methods for determining partial radial distribution functions using electrons are being investigated, using energy selected Electron back scatter diffraction electron diffraction combined with atomistic Dr. A.J. Wilkinson modelling. Refinement procedures are being developed which will allow differentiation between Electron back scatter diffraction patterns are used to alternative structural models. (*UKAEA, Culham) measure the orientations of individual grains and (Funded by JEOL) grain boundary misorientations in polycrystals. The method is being applied to characterise crystallographic textures in a variety of materials Disorder in complex oxides systems: Al-Li alloys, Ni-based superalloys, steels, Dr. J.L. Hutchison, Dr. J. Sloan metal-ceramic interfaces, and superconductors. New analysis methods are being developed for the Disorder in a variety of complex oxide structures measurement of small angle misorientations which include layered bismuthates, non- developed during plastic deformation and for the stoichiometric rutiles and tungsten oxides is being measurement of local elastic strain tensors. investigated by high resolution techniques using the Oxford JEOL 4000EX and 3000F ultra-high resolution instruments. (Funded by British Council) Multivariate analysis of EDS and EELS data Professor J.M. Titchmarsh Polyhedral and cylindrical metal chalcogenides The generation of large data sets by EDX and EELS Dr. J.L. Hutchison, Dr. J. Sloan, Professor R. Tenne* imaging and spectroscopy is now routine using modern analytical TEM methods. However, Closed polyhedral structures of the layered materials conventional processing of data cannot separate small WS2, MoS2 and other chalcogenides have recently signals from artefacts and noise and cannot always been discovered. They are in the form of concentric, detect correlations between signals. Multivariate polyhedral shells, somewhat similar to the analysis methods are being developed for routine "buckyball" and "fullerene" carbon cage compounds. handling of large data sets to improve the extraction Their formation and structures are being investigated of information from analytical EM data. (In by high resolution electron microscopy. Their collaboration with AEAT and INSS) possible use as high-performance solid lubricants is being investigated. (*Weizmann Institute, Israel)

Page 28 Characterisation

Development of an aberration-corrected Control of quantum dot growth by sub- electron microscope for high resolution surface dislocations analysis and imaging Professor D.J.H. Cockayne, C. Lang, Dr. D Nguyen- Professor D.J.H. Cockayne, Professor J.M. Manh*, Dr. F Ross** Titchmarsh, Dr. J.L. Hutchison, Dr. A.I. Kirkland, Dr. C.J.D. Hetherington The quantum dots (QDs) investigated in this work are nano-sized semiconductor islands which, due to their As part of a major research grant, the Department has size, exhibit novel electronic properties. They take secured funding which enables us to work closely microelectronics to the next stage of nanoelectronics. with an electron microscope manufacturer in QDs typically involve the growth of small islands of developing the next generation of high performance one semiconductor on another semiconductor acting electron microscopes. The new instrument includes a as a substrate. For progress in this field, it is necessary field-emission-gun, two aberration correctors and to develop methods for the controlled growth of QDs, various advanced detectors which will provide preferably in arrays. This project aims to study the analysis and spatial resolution capabilities a the 1 effectiveness of dislocations embedded in crystalline level. The instrument will be used for atomic-scale substrates as nucleation sources for the growth of investigations of a range of new materials. (Funded by QDs, and specifically their effectiveness in JIF) controlling the composition and sizes of the QDs. This will be done in a combined theoretical and experimental study in a collaboration between the Tilt- and through-focus series image University of Oxford, Culham Science Centre reconstruction techniques for super- (UKAEA), and IBM (Yorktown Heights, USA). reconstruction electron microscopy These three laboratories bring together a unique combination of materials characterisation, modelling Dr. A.I. Kirkland, Dr. J.L. Hutchison, Dr. J. Sloan, and in-situ observation during QD growth. Dr. R.R. Meyer, S. Haigh (*UKAEA, **IBM USA) We are developing numerical techniques for reconstructing exit-waves from crystals to enable us TEM investigation of stress corrosion to extract both the amplitudes and phases of diffracted cracking in Inconel 600 beams. In this way the useable information in lattice Dr. S. Lozano-Perez, Professor J.M. Titchmarsh, Dr. imaging from the JEOL 3000F instrument can be M.L. Jenkins, Dr. K. Fujii* extended out as far as 1Å. In the case of complex oxide structures the positions of the oxygen atoms are clearly revealed by this technique. (Funded by Intergranular stress corrosion cracking in Inconel 600 EPSRC, Leverhulme Trust and The Royal Society) in the heat exchangers and other components in the primary circuit of PWR power generating plant is an important safety issue. The project will develop Investigation of carbon nanotubes techniques for TEM specimen preparation using FIB produced by novel synthetic methods to allow investigation of the nucleation and growth of SCC. Characterisation of precipitation and Dr. J.L. Hutchison, Dr. J. Sloan, Professor N.A. segregation at boundaries will enable key Kiselev* microstructural factors to be identified that contribute to SCC. (Funded by INSS* and EPSRC) We are investigating the structure of carbon nanotubes prepared by various synthetic routes with the aims of controlling tube dimensions, and 3-D microstructural analysis using a FIB understanding growth mechanisms. (*Institute of system Crystallography, Russian Academy of Sciences) Dr. R.M. Langford, Professor J.M. Titchmarsh, Dr. B.J. Inkson*, Dr. G. Mšbus* Development of FIB machining technologies A focused ion-beam system is being used to mil a set of cross-sections through a chosen area. The images Dr. Y. Huang, Professor J.M. Titchmarsh, Professor obtained are being used to reconstruct the 3- D.J.H. Cockayne, Professor A.K. Petford-Long dimensional microstructure. The suitability of this technique to a range of different systems and the Development and application of focussed ion beam errors associated with the milling and the 3-D machining technology for the preparation of reconstruction are being assessed.(Funded by the specimens of analytical microscopy.(Funded by EPSRC)(*Department of Engineering Materials, EPSRC platform grant) University of Sheffield)

Page 29 Research In Progress 2004–2005

NanoSIMS analysis of metallic and Remote Microscopy electronic materials Professor D.J.H. Cockayne, Professor P. Jeffreys*, C.J. Dark, S. Ahmed, Dr. M. Kilburn, Professor Professor G.D.W. Smith, Dr. M Dovey*, Dr. A.I. C.R.M. Grovenor, Professor J.M. Titchmarsh Kirkland, Dr. R.R. Meyer

A Cameca NanoSIMS50 has recently been installed at Remote access to electron microscopes is being the Oxford University Begbroke Science Park. This developed. The aim is to develop a capability of equipment is a state-of-the-art machine for chemical persistent and pervasive access, using the e-Grid. A analysis with high spatial resolution and very high dedicated SEM has been installed, and remote access sensitivity for most elements. We will use this new is being "rolled out" to schools, and in time, to facility in projects where the accurate analysis of the museums and industry. (Funded by DTI and JEOL) distribution of dilute element is critical to developing a better understanding of the materials properties. Key projects include; Electron Energy Loss studies of nanostructures [1] Grain boundary doping studies in high Professor D.J.H. Cockayne, Dr. D. Nguyen Manh*, R. temperature superconductors (with University of Nicholls Augsburg), and of trace elements in polycrystalline silicon (with Professor S. Tsurekawa, Department of The electron energy loss fine structure of fullerenes Nanomechanics,Tohoku University) and other nanostructures is being investigated both [2] Analysis of the distribution of H in aluminium theoretically and experimentally, using high castings (in collaboration with Dr K O'Reilly) resolution energy loss techniques and DOS calculations. (*UKAEA, Culham) [3] The chemistry of trace elements in structural steels (in collaboration with Corus) [4] Impurity and light element analysis in MgB2 Interface Engineering of Multilayer wires and powders Nanostructures Professor M. Bilek*, A/Prof. D. McCulloch**, NanoSIMS analysis of Biological Materials Professor D.J.H. Cockayne, K. Smart, Dr. M. Kilburn, Professor C.R.M. Nanostructured multilayers can outperform coatings Grovenor, Dr. J.T. Czernuszka, Professor J. of their constituent layers in both hardness and Dilworth* strength. It is believed that the nature of interfaces in these materials is critical since they mediate A Cameca NanoSIMS50 has recently been installed at dislocation motion and crack propagation. This the Oxford University Begbroke Science Park. This project will use advanced synthesis, microanalysis is a state-of-the-art facility for chemical analysis with and theoretical methods to investigate multilayer high spatial resolution and very high sensitivity for coatings with sharp, diffuse and rough interfaces in most elements. 50% of the time on this new facility order to reveal their failure mechanisms under stress. will be dedicated to studies of biological materials. This will enable us to understand the principles Current projects include; the localisation of Rh required to design the strongest structures and complexes in a study of new imaging and therapeutic facilitate the selection of materials and deposition agents for hypoxic tissue. [Trace element localisation parameters in order to produce coatings optimised for in human hair and bone samples (in collaboration with a range of demanding applications (Funded by Proctor and Gamble, University of Manchester). ARC)(University of Sydney*, RMIT**) (*Department of Chemistry) Novel Approaches to Direct Object New Detectors for Transmission Electron Reconstruction in Transmission Electron Microscopy Microscopy Dr. A.I. Kirkland, Dr. R.R. Meyer Dr. A.I. Kirkland, Dr. R.R. Meyer

Current generation imaging detectors for All Transmission Electron Microscope Images are Transmission Electron Microscopy rely on a complex resolution limited by the aberrations of the objective electron-photon conversion chain with the photons lens. This project aims to develop novel approaches to being detected by Charge Coupled Devices. As a overcoming these limitations through direct result the overall sensitivity of these systems is poor reconstruction from combinations of imaging and they are limited in their framerate. We aim to experiments capable of achieving sub Angstrom construct the next generation of direct electron resolution and may be applicable to imaging and detector and this project will involve both diffraction using other radiation sources. (Funded by computation and ultimately fabrication of a prototype EPSRC) device. (Funded by Leverhulme Trust)

Page 30 Characterisation

High spatial resolution analysis of TMR Investigation of grain growth during structures fabriation of ferritic steel rod D. Kirk, Professor A.K. Petford-Long, Dr. M.T. Kief*, S. Ahmed, Professor J.M. Titchmarsh Dr. A.A. Morrone*, Dr. B. Karr* This project investigate the relationship between The first aim of this project is to develop advanced microstructural variations and mechanical properties TEM characterisation techniques that are specifically of ferritic steel rod, in particular, variations in grain tailored to the analysis of TMR structures. The second size will be correlation with segregation of low atomic aim is to provide structural, microchemical and number elements (B, N, C) using microanalytic micromagnetic analysis of TMR structures, at nm to techniques such as NanoSIMS, TEM, micro- sub-nm resolution, as a function of deposition diffraction etc. (Funded by Corus and EPSRC) (In conditions, anneal conditions and oxidation collaboration with Corus) conditions. These data will then be correlated with the bulk magnetic and transport properties of the TMR structures. (*Seagate Technology) (Funded by EPSRC Fundamentals of Aberration Corrected and Seagate Technology) Imaging in the TEM Dr. A.I. Kirkland Aberration-corrected high resolution The department has installed the worldÕs first electron microscopy electron microscope with aberration correctors in both Dr. J.L. Hutchison, Dr. A.I. Kirkland the condenser (probe-forming) and objective (image forming) lenses. This project aims to develop an We are exploring ways of exploiting the facility to understanding of the image contrast theory adjust spherical aberration in high resolution electron appropriate to this instrument, and to develop microscopy as a way of obtaining 0.1 nm resolution, experimental techniques for exploiting variable and also as a way of controlling phase contrast, aberration imaging. Possible materials candidates for particularly in the study of nanocrystalline particles in experimental and theoretical studies include complex the 1 - 2 nm size range. (Funded by EPSRC JIF) oxides and carbon nanotubes.

Gram quantities of pure carbon nanotubes TEM investigation of PRAM Materials and and related materials Devices Dr. N. Grobert Professor D.J.H. Cockayne, Dr. Se Ahn Song*

Pure and well-aligned carbon nanotubes can be The phase change memory device (PRAM) is prepared in gram quantities using homogenously considered as the next generation device which will dispersed aerosols generated from metalorganic compete with DRAM and Flash memory. Key precursor solutions using an ultrasonic spraying materials for the PRAM are thin films such as device. In addition, this process can also be adapted Ge2Sb2Te5. These alloys can have a range of possible for the synthesis of bulk amounts of nitrogen and amorphous structures, but understanding of the boron doped carbon nanotubes and composites of structure of such thin films is not at all carbon nanotubes with alumina, silicon carbide and straightforward because of the small volumes of other ceramic materials. SEM and TEM investigations material available for analysis in PRAM systems. reveal that the products are generally arranged in The radial distribution function technique using carpet-like flakes containing high yields of well energy selected electron diffraction has been graphitized polyhedral particles or amorphous carbon, developed specifically to give the radial distribution which are major drawbacks of standard production function (RDF) of thin films like those to be methods. With this method it is now possible to investigated in this project. The interpretation of the explore the chemical and physical properties of, for RDF from alloys is, however, not straightforward, and instance, CNx nanotubes and their composite studies of model systems will be required to materials without the influence of by-products or the confidently interpret the data. This will include need of additional purification processes. simulating the RDF from model structures, and also collecting data from binaries. HREM will also be used to study the structure of the thin films close to interfaces, if time allows. (*Samsung, Korea)

Page 31 Research In Progress 2004–2005

IV - RADIATION DAMAGE

Characterisation of defect clusters using Quantum Electron Microscope Imaging of elestic diffuse scattering patterns and Nanoclusters under Weak-Beam energy-filtered images Conditions Dr. M.L Jenkins, Professor A.P. Sutton, Z. Zhou, Dr. Dr. M.L. Jenkins, Professor A.P. Sutton, Professor S.L. Dudarev* J.M. Titchmarsh, Z. Zhou, Dr. S.L. Dudarev*

New electron-microscope characterisation techniques This project is focused on the development of a new based on energy-filtered imaging and diffraction are approach to the interpretation of electron microscope being developed. A particularly promising new images of nanoclusters. The approach is based on the technique (developed by Kirk) involves theory developed by Howie and Basinski, where measurements of elastic diffuse scattering near quantum interference between non-parallel diffracted weakly excited diffraction peaks from isolated small electron beams is taken into account. Our work point-defect clusters. The asymmetry in the diffuse involves development of a computer code scattering immediately reveals the interstitial or implementing the original Howie and Basinski vacancy nature of the cluster. This technique is now equations, to allow image simulations under weak- being explored systematically, including diffraction beam diffraction conditions of nanoclusters of pattern simulations.(*EURATOM/UKAEA) complex morphology. These image simulations will be matched with experimental images of small clusters produced by interaction of high-energy Mechanisms of embrittlement in reactor particles with metallic crystalline films. pressure vessel steels (*EURATOM/UKAEA) Dr. M.L. Jenkins, Professor J.M. Titchmarsh, Dr. S. Lozano-Perez

Electron microscopy of heat - treated and irradiated pressure vessel steels and model alloys is being carried out to identify the mechanisms by which these materials become embrittled during neutron irradiation, with particular emphasis on (i)the precipitation of copper-rich particles, and (ii)identification of the matrix component of hardening. Methods used include high-resolution electron microscopy, EELS mapping and in-situ straining. (Funded by EPSRC and Rolls-Royce)

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Page 32 Modelling and Simulation

G. Modelling and Simulation A materials modelling laboratory was set up in 1992 on the top floor of 21 Banbury Road. It currently houses a suite of Hewlett-Packard, Silicon Graphics and LinuxPC workstations. The laboratory acts as the focus for all computational modelling within the Department of Materials. It is a world-leading facility in that the research spans the entire spectrum from quantum mechanical atomistic simulations through the microscopic scale to macroscopic continuum modelling. The work of the laboratory supports and complements the in house experimental programmes and has close links with industry.

MBE growth of spintronic materials Dynamical Ising model simulations of Professor D.G. Pettifor, Dr. R. Drautz, D. Murdick*, phase separation Dr. X. Zhou*, Professor H. Wadley* Dr. G. Sha, A. Morley, Professor A. Cerezo, Dr. J.M. Hyde*, Professor G.D.W. Smith Analytic bond-order potentials (BOPs) are being developed for modelling the MBE growth of Monte Carlo simulations based on the dynamical spintronic materials such as Mn in GaAs films. Ising model are being used to study the early stages of (*University of Virginia) (Funded by DARPA). phase separation in simple alloys. The model is able to simulate spinodal decomposition in Fe-Cr, nucleation and growth in Cu-Co and Fe-Cu, and Modelling phase change materials simultaneous ordering and clustering in Ti-Al. The Professor D.G. Pettifor, Dr. V. Burlakov, Dr. K. results of the simulations are compared with Kohary, Dr. J.A. Brug*, Dr. T.C. Anthony*, Dr. C. experimental measurements of atomic-scale Moorhouse* composition variations, as determined by the 3- dimensional atom probe (PoSAP). (*BNFL Nuclear The electron transport of phase change materials is Sciences and Technology Services) (Funded by Rolls being modelled by a Monte Carlo model of film Royce) growth and a Tight Binding model of conduction. There is close collaboration with the experimental Atomic Resolution Storage group at HP Laboratory. Mapping of magnetisation distributions in (*HP Laboratories, Palo Alto) (Funded by HP thin layered films Laboratories) Professor A.K. Petford-Long, Dr. A. Kohn

Power dissipation in metallic nanowires We have developed a method for quantitative mapping of the magnetisation in thin magnetic Professor A.P. Sutton, Dr. T.N. Todorov* specimens at a high spatial resolution. The method is being used to study the magnetisation distribution in The purpose of this project is to implement a tight thin films and layered systems. In addition we are binding formalism to simulate power dissipation and applying and developing the Transport of Intensity local heating in current-carrying nanowires, and to Equation approach for reconstruction of quantitative combine the heating simulations with existing tight magnetic maps. (Funded by Hewlett-Packard Labs.) binding calculations of current-induced forces. (*Queen's University Belfast) (Funded by EPSRC) Fundamentals of brittle-ductile transitions Modelling photo-induced changes during Dr. S.G. Roberts, Professor Sir Peter Hirsch, Dr. A.J. Wilkinson growth of amorphous chalcogenide films Dr. K. Kohary, Professor D.G. Pettifor, Professor S. Cleavage failiure in the Brittle-transition of steels is Kugler* being treated in terms of a model in which the cleavage is initiated at a microcrack situated in the The photo-induced volume changes in amorphous stress field ahead of a macroscopic crack. The plastic chalcogenide semiconductors will be modelled using zone around the microcrack is modelled by computer a tight-binding molecular dynamics scheme in order simulations of dislocation arrays around the micro- to analyse the bond-breaking mechanisms responsible crack-tips. Dislocation shielding plays an important for the photo-induced instabilities. (*Budapest part in determining the fracture stress. The model University of Technology and Economics.) (Funded predicts a fracture stress independent of yield stress, by British Council). in accord with experiments. (Funded by EPSRC, AEAT and HSE)

Page 33 Research In Progress 2004–2005

Modelling carbon nanostructures for Modelling adhesion between polymers and quantum computing inorganic substrates Dr. S.M. Lee, R. Scipioni, D. Gunlycke, Dr. D. Professor A.P. Sutton, Dr. D.R. Mason, Dr. T.R. Nguyen Manh*, Professor D.G. Pettifor, Professor Walsh* G.A.D. Briggs A new strategy for modelling adhesion between Tight binding and ab initio density functional codes polymers and inorganic substrates has been are being used to predict the atomic and electronic developed. It is being applied to polymer adhesion structure and transport properties of single-wall issues of interest to the semiconductor industry. This carbon nanotubes containing endohedral fullerenes, project is part of an e-science collaboration called which are being investigated in-house for their 'RealityGrid', funded by EPSRC. (*Warwick quantum computing potential. (*UKAEA, Culham). University) (In collaboration with Loughborough and (Funded by EPSRC Foresight LINK Project, DTI and Manchester computing centres and UCL) Hitachi Europe). First principle studies of intermetallics Experimental and modelling studies of H.R. Chauke*, M. Phasha*, Professor P.E. Ngoepe*, excitonic and charge transport in the Dr. R. Drautz, Dr. D. Nguyen Manh**, Professor organic-inorganic composite solar device D.G. Pettifor K. Kawata, Dr. V.M. Burlakov, Dr. M. Carey, Professor A.P. Sutton, Professor G.A.D. Briggs, The electronic structure, equation of state and phase Professor I. Samuel* stability of platinum aluminides and magnesium- lithium alloys are being predicted using first Transport properties of excitons and holes in the principles density functional theory. (*Materials conducting polymer, and those of electrons in Modelling Centre, University of the North, South inorganic semiconductor are being studied using Africa; **UKAEA, Culham) (Funded by Royal spectroscopic and (photo)electrical measurements. Society - FRD collaborative project) Spectroscopic studies provide information about the diffusion coefficient of excitons and the charge Modelling secondary electron emission separation performance of the organic-inorganic interface. Experimentally determined transport from surfaces with inequivalent coefficients will be used in modelling of the solar terminations device performance as a function of its morphology. Dr. M.R. Castell, Professor A.P. Sutton (Funded by the Toppan Printing Company.)(*University of St Andrews) Objects with more that one type of surface termination, where there is a difference in the workfunction or potential of the terminations, give Architectures for Computation in the rise to "patch fields". The influence of these fields on Quantum Regime. secondary electron emission will be modelled. Dr. S.C. Benjamin

This project is concerned with the question, what is Current-induced effects in molecules the best (most natural) architectural scheme for Professor A.P. Sutton, M. Todorovic processing information at the quantum level? The issue is examined in two distinct contexts: processing Current-induced mechanical and heating effects in classical information (bits) with quantum-scale molecular systems are being modelled. structures, and processing of true quantum information (qubits). Although there are many topics of interest within this area, research into the "global Modelling short fatigue crack growth control" concept is currently of primary interest. through polycrystals Using this approach bit/qubits can be effectively Dr. A.J. Wilkinson, Joo Eun Lee manipulated even if they are too close together to address individually. However, fundamental issues Models are being developed for short fatigue crack must be addressed before this novel paradigm can be growth based on dislocation mechanics descriptions considered mature: to determine the minimum of crack - plastic zone - grain boundary interactions. space/time costs implied by adopting such a scheme, The effects of grain size, grain orientation, and grain to quantitatively analyse fault tolerance (esp. for QIP), boundary misorientation distributions are being and to understand relative merits of one-, two- and incorporated through a Monte-Carlo scheme allowing three-dimensional arrays. (Funded by The Royal the microstructure induced statistical variations in Society) short fatigue crack growth behaviour to be analysed.

Page 34 Modelling and Simulation

Quantitative Atomic resolution Imaging Simulations of TEM abberation corrected Dr. A.I. Kirkland images Professor J.M. Titchmarsh, L.Y. Chang, Dr. A.I. Almost all structural information derived from High Kirkland Resolution Electron Microscopy relies on qualitative matching of observed and calculated image contrast. This project will provide image simulations under This project aims to investigate the fundamental conditions now achievable in the recently installed reasons as to why the calculated and measured double Cs aberration corrected TEM in the intensities differ by significant amounts and to Department. develop quantitative approaches to image matching.

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Page 35 Research In Progress 2004–2005

H. Materials Science Based Archaeology The Materials Science Based Archaeology Group is concerned with the investigation of all aspects of the metallurgical process, from smelting to metal finishing, and from the first use of alloys in the 5th/4th millennia BC to the Industrial Revolution. The themes of the research can be broadly labelled as archaeological and metallurgical. In archaeology the research derives from post-excavation and museum-based projects involving the characterization of the products and residues of past metallurgical processes. The results are used to explore the place of metals in ancient economies and societies, how they were made, used, traded and re-cycled, how their properties were understood, and what processes were associated with their deposition and survival in the archaeological record. This work is supported by experiments designed to relate this material to the process variables which shaped its formation. These experiments also form a link with the metallurgical objectives of the group. These are to acquire a deep knowledge of the physical and mechanical metallurgy of the metals used in the past, so that we can see how they were understood in the past. The results can be surprising and demand novel research, for example to determine why some alloys have an exceptional ductility. This work also links directly with other areas of metallurgy by extending to 6x103 years the time range available for studying a variety of room temperature phenomena from corrosion to precipitation, and with results applicable in such diverse fields as electronic packaging and the storage of nuclear waste.

Non-ferrous and precious metallurgy in the Early metallurgy in the Upper Euphrates European Iron Age Basin Dr. J.P. Northover, P. Nagy*, P. Ramsl**, C. Dr. J.P. Northover, Dr. K. Prag*, Dr. G. Philip** Zingerle** Microanalysis and metallography have been used to The study of copper-based and precious metal alloys characterise the metalwork from a number of major from excavations and hoards of the pre-Roman Iron excavations in the Upper Euphrates basin. The sites Age is leading for the first time to an understanding straddle political and economic boundaries of the 3rd how these metals were made and traded in a period millennium B.C. during the period in which bronze when iron had become the dominant utilitarian metal. became the main utilitarian metal. The results have Material is now available to illustrate how production given us a new understanding of the way in which on individual sites was organised and what techniques bronze became part of the metal economy and have were used together. Attention is also focused on also focused our attention on the great importance of cemeteries to look for associations between gender recycling in these early cities. (*University of and status of individuals and the technical quality of Manchester; **Department of Archaeology, artefacts buried with them. (*Abteilung Ur-und University of Durham). Fruhgeschichte, Universitat Zurich, Switzerland; **Institut fur Ur-und Fruhgeschichte, Universitat Wien, Austria) Effects of cremation on copper alloys Dr. J.P. Northover

Application of microprobe and The effects of high temperatures on copper alloys in metallographic techniques to numismatic oxidising, neutral and reducing atmospheres is being problems studied by optical metallography and by experimental Dr. J.P. Northover, Dr. D.M. Metcalf*, Dr. C.E. replication. The results are used to determine the King*, Dr. L. Treadwell* placement of grave goods in cremation pyres to assist in interpreting the burial rites. (In collaboration with The Cameca SEMPROBE is used to study the copper- Wessex Archaeology) , silver- and gold-based alloys used for a variety of coinages. Current projects involve Roman base-silver Investigation of the changes in metal and coinages of the later 3rd century AD, the silver and base-metal coinages of medieval England, the coinage slag inclusion compositions during fire of the pre-Roman Iron Age, Indo-Greek and Islamic welding. coinages. Very large databases of analyses have been C.J. Salter, Dr. B.J.J. Gilmour and are being assembled in all these areas and attention is now directed to new methods for A study of the changes in metal and slag inclusion interrogating these. (*Ashmolean Museum, Oxford) compositions that occur during the forge welding of iron. In particular those changes seen in a variety of Anglo-Saxon phosphoritic/non - phosphoritic composite iron artefacts.

Page 36 Materials Science Based Archeology

Application of the scanning proton The development of iron and steel for microprobe to the analysis of ancient structural and railway use in the 19th bronze century. Dr. J.P. Northover, Dr. G.W. Grime*, M.H. Abraham Dr. J.P. Northover

The requirements of museum collections have Rails and structural iron and steelwork surviving from stimulated this project in non-destructive and the nineteenth century are often well dated and minimally destructive analysis of ancient bronze. The provenanced to specific ironworks. They offer an aim is to use a laser to mill sub-millimetre diameter ideal means of studying developments in the windows in the patina on selected bronzes and then capabilities of, successively bloomery iron, puddled use the SPM to analyse the metal as it is exposed, iron and Bessemer steel for such products. A with the X-ray mapping facility employed to make successful pilot project has led to new connections so basic metallographic observations. An experimental that, for instance, it will be possible to compare programme will develop the best mode of operation practice in Britain and France and assess the quality of the analyses in comparison with sample-based analysis. (*University of Surrey) The use of high resolution scanning Auger microscopy to characterise internal Study of the products of the experimental corrosion in archaeological bronze reproduction of the iron-working process at Dr. J.P. Northover*, Dr. E. Paparazzo*, Dr. D. Bryn Y Castell and Crawcwellt Sites, Baer**, Dr. S. Lea** Gwynedd C.J. Salter, P. Crew* The mechanisms of long-term corrosion processes of buried bronze surfaces are beginning to be well A series of iron smelting and smithing experiments understood. Much less clear are those involved in sub- have been carried out to reproduce the metal and other surface and internal inter- and transgranular corrosion iron-working debris from these important Iron Age in the same objects. The approach used here is to sites. Presently, this material is being studied, an maximise the resolution obtainable with scanning attempt to fully understand the chemistry, Auger microscopy in mapping corrosion species at microstructure and mechanical properties of the grain boundaries in bulk samples. Resolutions of the different types of iron and steel produced. order of 10nm have been obtained in elemental (*Snowdonia National Park Study Centre, mapping; the interpretation of these maps is now Maentwrog, Gwynedd) being developed. (*ISM-CNR, Frascati, Roma, Italy; **Pacific Northwest National Laboratory, Richland, WA, USA) Copper extraction at Ross Island, Co. Kerry, Ireland A study of Byzantine copper alloy C.J. Salter, Dr. J.P. Northover, Dr. W. O'Brien* metalwork A project to characterise copper and associated Dr. J.P. Northover, Dr. M. Saghieh Beydoun* residues produced from the earliest copper mine in Ireland, dating to the second half of the third An analytical and metallographic study of early millennium BC. (*National University of Ireland, Byzantine copper alloy metalwork based on the Galway) excavations in Beirut. The site was sealed by an earthquake in 551 AD so this study enables us to characterise everyday Byzantine metalwork at a The characterisation of Islamic steels particular moment in time. (*Lebanese University, Dr. B.J. Gilmour, C. J. Salter, Dr. J. Allan* Beirut) (Funded by British Council)

A long-term project to develop the characterisation of Metalwork of the Bronze Age-Iron Age high carbon and alloy steels from the medieval Islamic world using a range of metallographic and transition in Britain microprobe techniques. (*Department of Eastern Art, Dr. J.P. Northover, D. Bruns* Ashmolean Museum) Combining archaeological and metallurgical methods to understand metalwork and metalworking in Britain at the time of the first introduction of iron in the 8th- 6th centuries BC. This is the first ever systematic survey of this material. (*Institute of Archaeology, University of Oxford)

Page 37 Research In Progress 2004–2005

Publications

Adamson, D.H., Angelescu, D.E., Waller, J., Bhutto, A.A., Vesely, D. and Gabrys, B.J.: Pelletier, V., Trawick, M.L., Register, R.A. and 'Miscibility and interactions in polystyrene and Chaikin, P.M.: 'Long range ordering of block sodium sulfonated polystyrene with poly(vinyl copolymer microstructures in thin films.' Abstracts methyl ether) PVME blends. Part II. FTIR.' Polymer Of Papers Of The American Chemical Society 226 44 (21) (2003) 6627-6631. (2003) 234-POLY. Briceno-Gomez, M., Brown, P.M., Titchmarsh, Adelmann, C., Daudin, B., Oliver, R.A., Briggs, J.M., Ahmed, S. and Schumacher, P. (2004). G.A.D. and Rudd, R.E.: 'Nucleation and growth of Microstructural characterisation of a rapidly GaN/AlN quantum dots.' Physical Review B 70 solidified NiMo steel. Electron Microscopy And (2004) 125427. Analysis 2003: 257-260.

Assender, H.: 'The joys of parenthood.' Physics Briggs, E.P.K., M., Walpole, A.R., Palsgard, E. and World 17 (3) (2004) 60-60. Wilshaw, P.R.: 'Formation of highly adherent nano- porous alumina on Ti-based substrates: a novel bone Audebert, F., Mendive, C. and Vidal, A.: 'Structure implant coating.' Journal Of Materials Science: and mechanical behaviour of Al-Fe-X and Al-Ni-X Materials in Medicine 15 (2004) 1-9. rapidly solidified alloys.' Materials Science And Engineering A-Structural Materials Properties Britz, D.A., Khlobystov, A.N., Wang, J.W., O'Neil, Microstructure And Processing 375-77 (2004) 1196- A.S., Poliakoff, M., Ardavan, A. and Briggs, G.A.: 1200. 'Selective host-guest interaction of single-walled carbon nanotubes with functionalised fullerenes.' Bagot, P.A.J.: 'Fundamental surface science studies Chemical Communications (2) (2004) 176-177. of automobile exhaust catalysis.' Materials Science And Technology 20 (6) (2004) 679-694. Bromwich, T.J., Bucknall, D.G., Warot, B., Petford- Long, A.K. and Ross, C.A. (2004). TEM analysis Baik, K.H., Grant, P.S. and Cantor, B.: 'The and fabrication of magnetic nanoparticles. Electron equiaxed-banded microstructural transition during Microscopy And Analysis 2003: 95-98. low pressure plasma spraying.' Acta Materialia 52 (1) (2004) 199-208. Browne, D.J. and Hunt, J.D.: 'A fixed grid front- tracking model of the growth of a columnar front Barkay, Z., Grunbaum, E., Shapira, Y., Wilshaw, P., and an equiaxed grain during solidification of an Barnham, K., Bushnell, B., Ekins-Daukes, N.J. and alloy.' Numerical Heat Transfer Part B- Mazzer, M. (2004). High-resolution scanning Fundamentals 45 (5) (2004) 395-419. electron microscopy of dopants in p-i- n junctions with quantum wells. Electron Microscopy And Bucknall, D.G.: 'Influence of interfaces on thin Analysis 2003: 143-146. polymer film behaviour.' Progress In Materials Science 49 (5) (2004) 713-786. Baxter, R.J., Pettifor, D.G., Tsymbal, E.Y., Bozec, D., Matthew, J.A.D. and Thompson, S.M.: Bucknall, D.G. and Anderson, H.L.: 'Polymers get 'Importance of the interband contribution to the organized.' Science 302 (5652) (2003) 1904-1905. magneto- refractive effect in Co/Cu multilayers.' Journal Of Physics-Condensed Matter 15 (45) Burlakov, V.M., Briggs, G.A.D., Sutton, A.P., (2003) L695-L702. Bongiorno, A. and Pasquarello, A.: 'Modelling phase separation in non-stoichiometric silica.' Baxter, R.J., Rudolf, P., Teobaldi, G. and Zerbetto, Physical Review Letters 93 (2004) 1335501. F.: 'Modelling of the adsorption of C-60 on the Au(110) surface.' Chemphyschem 5 (2) (2004) 245- Burlakov, V.M., Norenberg, H., Briggs, G.A.D. and 248. Tsukahara, Y.: 'Model for the pressure-dependent permeation of small molecules through a polymer Benjamin, S.C.: 'Multi-qubit gates in arrays coupled membrane.' Journal Of Polymer Science Part B- by 'always-on' interactions.' New Journal Of Physics Polymer Physics 41 (12) (2003) 1308-1315. 6 (2004) art. no.-61.

Page 38 Publications

Burlakov, V.M., Sutton, A.P., Briggs, G.A.D. and Chen, K.H., Liu, H.W., Zhang, Z., Li, S. and Todd, Tsukahara, Y. (2003). Simulation of porus SiOx R.I.: 'The improvement of constituent dissolution layer growth. International Conference on Modeling and mechanical properties of 7055 aluminum alloy and Simulation of Microsystems Technical by stepped heat treatments.' Journal Of Materials Proceedings. Laudon, M. and Romanowicz, B.: 95- Processing Technology 142 (1) (2003) 190-196. 97. Cizek, P., McKay, B.J. and Lozano-Perez, S. Cantor, B., Chang, I.T.H., Knight, P. and Vincent, (2004). Investigation of the interfaces between A.J.B.: 'Microstructural development in equiatomic boride particles and aluminium in the As-received multicomponent alloys.' Materials Science And and Re-melted Ti-B-Al grain refiner master alloy. Engineering A-Structural Materials Properties Electron Microscopy And Analysis 2003: 429-432. Microstructure And Processing 375-77 (2004) 213- 218. Cockayne, D.J.H., Doeblinger, M., Marsh, C. and Nguyen-Manh, D. (2003). The characterisation of Cantor, B., Dunne, F.P.E. and Stone, I.C. (2004). amorphous nanovolumes using RDF electron Metal and Ceramic Composites. Bristol, IoP diffraction. BCEIA. publishing. Costa, P., Sloan, J., Hutchison, J.L. and Green, Carey, M.J., Burlakov, V.M., Henry, B.M., Kirov, M.L.H.: 'Encapsulation of quaternary 1D K.R., Webster, G.R., Assender, H.E., Briggs, pentlandite-type alloy crystals within conical multi- G.A.D., Burn, P.L. and Grovenor, C.R.M. (2004). layer carbon nanotubes.' Chemical Communications Nanocomposite titanium dioxide/polymer (18) (2003) 2276-2277. photovoltaic cells: effects of TiO2 microstructure, time and illumination power. Organic Photovoltaics Dal Don, B., Kohary, K., Tsitsishvili, E., Kalt, H., 4: Proc. SPIE. Kafafi, Z.H. and Lane, P.A. 5215. Baranovskii, S.D. and Thomas, P.: 'Quantitative interpretation of the phonon-assisted redistribution Carter, R., Sloan, J., Kirkland, A.I., Meyer, R.R., processes of excitons in Zn1-xCdxSe quantum Hutchison, J.L. and Green, M.L.H. (2004). A one- islands.' Physical Review B 69 (4) (2004) art. no.- dimensional semiconductor crystal with 045318. differentially rotating atomic layers formed within a single-walled carbon nanotube. Proceedings of the Davies, T.J., Brookes, B.A., Fisher, A.C., Yunus, 13th Electron Microscopy Conference. Antwerp, K., Wilkins, S.J., Greene, P.R., Wadhawan, J.D. and Belgium. 2: 351. Compton, R.G.: 'A computational and experimental study of the cyclic voltammetry response of Castell, M.R.: 'Wulff shape of microscopic voids in partially blocked electrodes. Part II: Randomly UO2 crystals.' Physical Review B 68 (23) (2003) distributed and overlapping blocking systems.' art. no.-235411. Journal Of Physical Chemistry B 107 (26) (2003) 6431-6444. Chang, L.Y., Chen, F.R., Kirkland, A.I. and Kai, J.J.: 'Calculations of spherical aberration-corrected Davin, L., Cerezo, A., Gao, N. and Starink, M.: imaging behaviour.' Journal Of Electron Microscopy 'Characterization of the precipitation in Al-Li-Cu- 52 (4) (2003) 359-364. Mg-(Mn, Zr) alloys.' Surface And Interface Analysis 36 (5-6) (2004) 589-593. Chang, L.Y., Meyer, R.R. and Kirkland, A.I. (2004). Calculations of limited coherence for high de Laissardiere, G.T., Nguyen-Manh, D. and resolution electron microscopy. Electron Mayou, D.: 'Effective medium-range Mn-Mn pair Microscopy And Analysis 2003: 345-348. interaction induces pseudogap in the density of states of Al(Si)-Mn approximants.' Journal Of Non- Chang, L.Y., Meyer, R.R. and Kirkland, A.I. (2004). Crystalline Solids 334 (2004) 347-351. Models of coherence for High Resolution Electron Microscopy. Proceedings of the 13th Electron Djuric, Z.: 'Three-dimensional simulation of liquid Microscopy Conference. Antwerp, Belgium. 2: 435. metal spray deposition onto arbitrary surfaces.' Modelling And Simulation In Materials Science Chen, F.R., Chang, L.Y. and Kirkland, A.I.: And Engineering 12 (3) (2004) 529-544. 'Calculations of spherical aberration-corrected imaging behaviour.' Journal Of Electron Microscopy Djuric, Z. and Grant, P.: 'An inverse problem in 52 (359) (2003) modelling liquid metal spraying.' Applied Mathematical Modelling 27 (5) (2003) 379-396.

Page 39 Research In Progress 2004–2005

Doblinger, M., Cockayne, D.J.H., Meyer, R.R., Friedrichs, S., Philp, E., Meyer, R.R., Sloan, J., Kirkland, A.I. and Nguyen-Manh, D. (2004). Kirkland, A.I., Hutchison, J.L. and Green, M.L.H. Induced order in intergranular films in Si3N4 (2004). LaI2@(18,3)SWNT: the crystallisation ceramics. Proceedings of the 13th Electron behaviour of a LaI2 fragment, confined within a Microscopy Conference. Antwerp, Belgium. 2: 59. single-walled carbon nanotube. Electron Microscopy And Analysis 2003: 455-458. Doblinger, M., Marsh, C.D., Nguyen-Manh, D., Ozkaya, D. and Cockayne, D.J.H. (2004). Fullagar, W.K., Aberdeen, K.A., Bucknall, D.G., Intergranular films in Si3N4 studied by TEM. Kroon, P.A. and Gentle, I.R.: 'Conformational Electron Microscopy And Analysis 2003: 401-404. changes in SP-B as a function of surface pressure.' Biophysical Journal 85 (4) (2003) 2624-2632. Doblinger, M., Wittmann, R. and Grushko, B.: 'Initial stages of the decomposition of the decagonal Gabrys, B.J., Bhutto, A.A., Bucknall, D.G., phase in the system Al-Ni-Fe.' Journal Of Alloys Braiewa, R., Vesely, D. and Weiss, R.A.: 'Neutron And Compounds 360 (1-2) (2003) 162-167. reflectivity studies of ionomer blends.' Applied Physics A-Materials Science & Processing 74 Doherty, M. and Sykes, J.M.: 'Micro-cells beneath (2002) S336-S338. organic lacquers: a study using scanning Kelvin probe and scanning acoustic microscopy.' Corrosion Galano, M., Audebert, F., Cantor, B. and Stone, I.: Science 46 (5) (2004) 1265-1289. 'Structural characterisation and stability of new nanoquasicrystalline Al-based alloys.' Materials Dong, H.B., Shin, M.R.M., Kurum, E.C., Cama, H. Science And Engineering A-Structural Materials and Hunt, J.D.: 'Determination of liquid fraction Properties Microstructure And Processing 375-77 during solidification of aluminium alloys using a (2004) 1206-1211. single-pan scanning calorimeter.' Fluid Phase Equilibria 212 (1-2) (2003) 199-208. Gao, Y.H., Shindo, D. and Petford-Long, A.K.: 'Nonuniform magnetic structure in Nd2Fe14B/Fe3B Dreger, S.A., Sachlos, E., Young, R.J., Czernuszka, nanocomposite materials.' Journal Of Applied J.T., Chester, A., Taylor, P. and Yacoub, M.H. Physics 93 (10) (2003) 8119-8121. (2004). Discerning mechanical properties of 3-D biological scaffolds seeded with porcine aortic valve Giannattasio, A., Murphy, J.D., Senkader, S., interstitial cells. Advances in Tissue Engineering Falster, R.J. and Wilshaw, P.R. (2004). Impurity and Biology of Heart Valves. Florence. Locking of Dislocations in Silicon. Electrochemical Society Proceedings "High Purity Silicon": 39-54. Dreger, S.A., Thomas, P., Sachlos, E., Chester, A., Czernuszka, J.T., Taylor, P. and Yacoub, M.H. Giannattasio, A., Senkader, S., Falster, R.J. and (2004). Matrix remodelling and synthesis by human Wilshaw, P.R.: 'Dislocation locking by nitrogen valve intertitial cells in a 3-D biological scaffold. impurities in FZ-silicon.' Physica B-Condensed 9th Biennial Meeting of the International Society for Matter 340 (2003) 996-1000. Applied Cardiovascular Biology. Savannah, Georgia. Giannattasio, A., Senkader, S., Falster, R.J. and Wilshaw, P.R.: 'The role of prismatic dislocation Enayati, M.H., Schumacher, P. and Cantor, B.: loops in the generation of glide dislocations in Cz- 'Amorphization of Ni60Nb20Zr20 by mechanical silicon.' Computational Materials Science 30 (1-2) alloying.' Materials Science And Engineering A- (2004) 131-136. Structural Materials Properties Microstructure And Processing 375-77 (2004) 812-814. Giovanelli, D., Lawrence, N.S., Wilkins, S.J., Jiang, L., Jones, T.G.J. and Compton, R.G.: 'Anodic Erlat, A.G., Henry, B.M., Grovenor, C.R.M., stripping voltammetry of sulphide at a nickel film: Briggs, A.G.D., Chater, R.J. and Tsukahara, Y.: towards the development of a reagentless sensor.' 'Mechanism of water vapor transport through Talanta 61 (2) (2003) 211-220. PET/AlOxNy gas barrier films.' Journal Of Physical Chemistry B 108 (3) (2004) 883-890. Givargizov, E.I., Stepanova, A.N., Aksenova, L.L., Rakova, E.V., Hatchison, J.L., Kiselev, N.A., Friedrichs, S., Kirkland, A.I. and Green, M.L.H. Mashkova, E.S. and Molchanov, V.A.: 'Nucleation (2004). Combined characterisation of the structural and growth of crystalline diamond particles on and physical properties of single walled cardbon silicon tips.' Crystallography Reports 47 (2002) nanotube composites. Proceedings of the 13th S159-S168. Electron Microscopy Conference. Antwerp, Belgium. 2: 317.

Page 40 Publications

Gotora, D. and Czernuszka, J.T. (2004). Hsieh, W.K., Chen, F.R., Kai, J.J. and Kirkland, A.I. Mineralization and cross-linking techniques to (2004). Resolution extrension and exit wave improve the mechanical properties of collagenn- reconstruction in complex HREM. APEM, Japan calcium phosphate (Coll-CaP) composites to be Society for Microscopy. used as bone analogues. TCES. Hudson, T.S., Dudarev, S.L. and Sutton, A.P. Gotora, D. and Czernuszka, J.T. (2004). (2004). Confinement of interstitial cluster diffusion Mineralization and cross-linking techniques to by oversized solute atoms. Proceedings of the Royal improve the mechanical properties of collagenn- Society. A460: 2457-2475. calcium phosphate (Coll-CaP) composites to be used as bone analogues. European Cells and Humphreys, E.S., Fletcher, H.A., Hutchins, J.D., Materials. Davos, Switzerland. Garratt-Reed, A.J., Reynolds, W.T., Aaronson, H.I., Purdy, G.R. and Smith, G.D.W.: 'Molybdenum Gotora, D. and Czernuszka, J.T.: 'Mineralization accumulation at Ferrite: Austenite interfaces during and cross-linking techniques to improve the isothermal transformation of an Fe-0.24 Pct C-0.93 mechanical properties of collagenn-calcium Pct Mo alloy.' Metallurgical And Materials phosphate (Coll-CaP) composites to be used as bone Transactions A-Physical Metallurgy And Materials analogues.' IoM3 Materials Congress (2004) Science 35A (4) (2004) 1223-1235.

Griffiths, S., Whittle, D., Ridley, N. and Todd, R.I. Husek, I., Kovac, P., Grovenor, C.R.M. and (2003). Superplasticity in commercial Al 7475. Goodsir, L.: 'Microhardness as a tool for filament Superplasticity In Advanced Materials. 447-4: 283- density and metal sheath analysis in MgB2/Fe(Cu) 288. wires.' Superconductor Science & Technology 17 (2004) 971-976. Grovenor, C.R.M., Goodsir, L., Salter, C.J., Kovac, P. and Husek, I.: 'Interfacial reactions and oxygen Hutchison, J.L., Allsop, N., Kirkland, A.I., distribution in MgB2 wires in Fe, stainless steel and Hetherington, C.J.D., Titchmarsh, J.M., Cockayne, Nb sheaths.' Superconductor Science & Technology D.J.H. and Dobson, P.J. (2004). Optimisd HREM 17 (3) (2004) 479-484. imaging of CdSe nanoparticles. Proceedings of the 13th Electron Microscopy Conference. Antwerp, Grushko, B. and Doblinger, M.: 'Decagonal Belgium. 2: 93. quasicrystals in Al-Ni-Co: generality and particulars.' Zeitschrift Fur Kristallographie 219 (7) Hutchison, J.L., Kirkland, A.I., Sloan, J. and Green, (2004) 447-455. M.L.H. (2004). Growing 1D crystals inside carbon nanotubes: new nanostructures from old materials. Hegedus, J., Kohary, K. and Kugler, S.: Proceedings of the 13th Electron Microscopy 'Comparative analysis of different preparation Conference. Antwerp, Belgium. 2: 93. methods of chalcogenide glasses: molecular dynamics structure simulations.' Journal Of Non- Hutchison, J.L., Sloan, J., Kirkland, A.I., Green, Crystalline Solids 338-40 (2004) 283-286. M.L.H. and Green, M.L.H.: 'Growing and characterizing one-dimensional crystals within Hegedus, J., Kohary, K., Kugler, S. and Shimakawa, single-walled carbon nanotubes.' Journal Of K.: 'Photo-induced volume changes in selenium. Electron Microscopy 53 (2) (2004) 101-106. Tight-binding molecular dynamics study.' Journal Of Non-Crystalline Solids 338-40 (2004) 557-560. Jagutzki, O., Schmidt-Bocking, H., Mergel, V., Cerezo, A. and Huang, M. (2003). Device and Hetherington, C.J.D. (2004). Strategies for one method for two-dimensional detection of particles. angstrom resolution. Electron Microscopy And U.S, P., 661,013. Analysis 2003: 219-224. Jo, M.H., Blamire, M.G., Ozkaya, D. and Petford- Hetherington, C.J.D., Hutchison, J.L., Lebedev, Long, A.K.: 'Spin- and charge-modulated trilayer A.A., Mosina, G.N., Savkina, N.S., Sloan, J. and magnetic junctions: Sorokin, L.M. (2003). Characterization of a porous La0.7Ca0.3MnO3/La0.45Ca0.55MnO3/La0.7Ca0.3 silicon carbide layer produced on a 6H-SiC MnO3.' Journal Of Physics-Condensed Matter 15 substrate: TEM (XHREM) and EDX studies. (30) (2003) 5243-5251. Microscopy Of Semiconducting Materials 2003: 73- 78. Jones, P.D.A., Duncan, S.R., Rayment, T. and Grant, P.S.: 'Control of temperature profile for a Hsieh, W.K., Chen, F.R., Kai, J.J. and Kirkland, spray deposition process.' Ieee Transactions On A.I.: 'Resolution extension and exit wave Control Systems Technology 11 (5) (2003) 656-667. reconstruction in complex HREM.' Ultramicroscopy 98 (2-4) (2004) 99-114.

Page 41 Research In Progress 2004–2005

Justice, I., Derby, B., Davis, G., Anderson, P. and Kim, K.B., Warren, P.J. and Cantor, B.: 'Glass- Elliott, J.: 'Characterisation of void and forming ability of novel multicomponent reinforcement distributions in a metal matrix (Ti33Zr33Hf33)- (Ni50Cu50)-Al alloys developed composite by X-ray edge-contrast by equiatomic substitution.' Materials Science And microtomography.' Scripta Materialia 48 (9) (2003) Engineering A-Structural Materials Properties 1259-1264. Microstructure And Processing 375-77 (2004) 317- 321. Kanai, M., Porfyrakis, K., Briggs, A.D. and Dennis, T.J.S.: 'Purification by HPLC and the UV/Vis Kirk, M.A., Davidson, R.S., Jenkins, M.L. and absorption spectra of the nitrogen-containing incar- Twesten, R.D. (2004). Diffuse Electron Scattering fullerenes iNC(60), and iNC(70).' Chemical by Nanometer-sized Defects in Gold and Tantalum. Communications (2) (2004) 210-211. Mat. Res. Soc. Symp. Proc. 792: 229.

Kanaya, T., Miyazaki, T., Watanabe, H., Nishida, Kirkland, A.I. and Meyer, R.R. (2004). Indirect K., Yamana, H., Tasaki, S. and Bucknall, D.B.: transmission electron microscopy; Aberration 'Annealing effects on thickness of polystyrene thin measurement and compensation and exit wave films as studied by neutron reflectivity.' Polymer 44 reconstruction. Electron Microscopy And Analysis (14) (2003) 3769-3773. 2003: 331-336.

Khlobystov, A.N., Britz, D.A., Ardavan, A. and Kirkland, A.I. and Meyer, R.R.: '"Indirect" high- Briggs, G.A.D.: 'Observation of ordered phases of resolution transmission electron microscopy: fullerenes in carbon nanotubes.' Physical Review Aberration measurement and wavefunction Letters 92 (24) (2004) art. no.-245507. reconstruction.' Microscopy And Microanalysis 10 (4) (2004) 401-413. Khlobystov, A.N., Britz, D.A., O'Neil, A.S., Wang, J., Poliakoff, M. and Briggs, G.A.D.: 'Low Kirkland, A.I., Meyer, R.R., Cockayne, D.J.H., temperature assembly of fullerene arrays in single- Hetherington, C.J.D., Hutchison, J.L. and walled carbon nanotubes using supercritical fluids.' Titchmarsh, J.M. (2004). Exit wave reconstruction Journal of Materials Chemistry 14 (2004) 2852- using an energy filtered aberration corrected TEM. 2857. Proceedings of the 13th Electron Microscopy Conference. Antwerp, Belgium. 2: 49. Khlobystov, A.N., Porfyrakis, K., Kanai, M., Britz, D.A., Ardavan, A., Shinohara, H., Dennis, T.J.S. Kirkland, A.I., Titchmarsh, J.M., Hutchison, J.L., and Briggs, G.A.D.: 'Molecular motion of Cockayne, D.J.H., Hetherington, C.J.D., Doole, endohedral fullerenes in single-walled carbon R.C., Sawada, H., Haider, M. and Hartel, P.: 'A nanotubes.' Angewandte Chemie-International double aberration corrected, energy filtered Edition 43 (11) (2004) 1386-1389. HREM/STEM.' Jeol News 39 (1) (2004) 2.

Khlobystov, A.N., Scipioni, R., Nguyen-Manh, D., Kirov, K.R. and Assender, H.E.: 'Quantitative ATR- Britz, D.A., Pettifor, D.G., Briggs, G.A.D., Lyapin, IR analysis of anisotropic polymer films: Extraction S.G., Ardavan, A. and Nicholas, R.J.: 'Controlled of optical constants.' Macromolecules 37 (3) (2004) orientation of ellipsoidal fullerene C-70 in carbon 894-904. nanotubes.' Applied Physics Letters 84 (5) (2004) 792-794. Kiselev, N.A., Hutchison, J.L., Moravsky, A.P., Rakova, E.V., Dreval, E.V., Hetherington, C.J.D., Khlobystov, A.N., Scipioni, R., Porfyrakis, K., Zakharov, D.N., Sloan, J. and Loutfy, R.O.: 'Carbon Britz, D.A., Lyapin, S.G., Wiltshire, J.G., Ardavan, micro- and nanotubes synthesized by PE-CVD A., Nguyen-Manh, D., Nicholas, R.J., Pettifor, D.G., technique: Tube structure and catalytic particles Kanai, M., Dennis, T.J.S., Shinohara, H. and Briggs, crystallography.' Carbon 42 (1) (2004) 149-161. G.A.D.: 'Ordering and interaction of molecules encapsulated in carbon nanotubes.' Materials Kohary, K., Cordes, H., Baranovskii, S.D., Thomas, Science and Technology 20 (2004) 969-974. P. and Wendorff, J.H.: 'Hopping transport in 1D chains (DNA vs. DLC).' Physica Status Solidi B- Kim, K.B., Ko, B.C. and Pak, S.J.: 'Formation of Basic Research 241 (1) (2004) 76-82. nanocrystals in Ti78Fe15Si7 amorphous alloy with a wide supercooled liquid region.' Materials Science Kohary, K. and Kugler, S.: 'Growth of amorphous And Engineering A-Structural Materials Properties silicon: Low energy molecular dynamics simulation Microstructure And Processing 366 (2) (2004) 421- of atomic bombardment.' Molecular Simulation 30 425. (1) (2004) 17-22.

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Kovac, P., Husek, I., Melicek, T., Grovenor, Liao, X.Z., Zou, J., Cockayne, D.J.H. and C.R.M., Haigh, S. and Jones, H.: 'Improvement of Matsumura, S.: '[001] zone-axis bright-field the current carrying capability of ex-situ MgB2 diffraction contrast from coherent Ge(Si) islands on wires by normal particale additions.' Superconductor Si(001).' Ultramicroscopy 98 (2-4) (2004) 239-247. Science & Technology 17 (2004) 1225. Lo, C.C.H., Scruby, C.B. and Smith, G.D.W.: Kugler, S., Kohary, K., Kadas, K. and Pusztai, L.: 'Dependences of magnetic Barkhausen emission and 'Unusual atomic arrangements in amorphous magnetoacoustic emission on the microstructure of silicon.' Solid State Communications 127 (4) (2003) pearlitic steel.' Philosophical Magazine 84 (18) 305-309. (2004) 1821-1839.

Kugler, S., Kohary, K., Kadas, K. and Pusztai, L.: Lovett, B.W., Reina, J.H., Nazir, A. and Briggs, 'Small bond angles in amorphous silicon: are they a G.A.D.: 'Optical schemes for quantum computation new type of defect?' Journal Of Non-Crystalline in quantum dot molecules.' Physical Review B 68 Solids 338-40 (2004) 425-429. (20) (2003) art. no.-205319.

Lang, C., Hirsch, P.B. and Cockayne, D.J.H.: 'On Lozano-Perez, S. and Titchmarsh, J.M.: 'TEM the core structure of 1/2 < 112] edge dislocations in investigations of intergranular stress corrosion gamma- TiAl.' Philosophical Magazine Letters 84 cracking in austenitic alloys in PWR environmental (3) (2004) 139-148. conditions.' Materials At High Temperatures 20 (4) (2003) 573-579. Lang, C., Nguyen-Manh, D. and Cockayne, D.J.H. (2003). GeSi quantum dots: the effect of alloying on Lozano-Perez, S., Titchmarsh, J.M. and Jenkins, the shape transformation. Microscopy Of M.L. (2004). Energy-Filtered imaging of Cu- Semiconducting Materials 2003: 99-102. nanoprecipitates. Electron Microscopy And Analysis 2003: 241-244. Lang, C., Nguyen-Manh, D. and Cockayne, D.J.H.: 'Nonuniform alloying in Ge(Si)/Si(001) quantum Lozano-Perez, S., Titchmarsh, J.M. and Jenkins, dots.' Journal Of Applied Physics 94 (11) (2003) M.L. (2004). TEM characterization of stress 7067-7070. corrosion cracks in 304SS. Electron Microscopy And Analysis 2003: 233-236. Lang, C., Nguyen-Manh, D. and Cockayne, D.J.H. (2004). The non-uniform composition profile in Ma, W.W., Yang, Y., Chong, C.T., Eggeman, A., Ge(Si)/Si(001) quantum dots. Electron Microscopy Piramanayagam, S.N., Zhou, T.J., Song, T. and And Analysis 2003: 35-38. Wang, J.P.: 'Synthesis and magnetic behavior of self-assembled Co nanorods and nanoballs.' Journal Larson, D.J., Petford-Long, A.K., Ma, Y.Q. and Of Applied Physics 95 (11) (2004) 6801-6803. Cerezo, A.: 'Information storage materials: nanoscale characterisation by three-dimensional Mallik, K., Falster, R.J. and Wilshaw, P.R.: atom probe analysis.' Acta Materialia 52 (10) (2004) 'Schottky diode back contacts for high frequency 2847-2862. capacitance studies on semiconductors.' Solid-State Electronics 48 (2) (2004) 231-238. Lee, S.M., Lee, S.H. and Scheffler, M.: 'Adsorption and diffusion of a Cl adatom on the GaAs(001)- Mason, D.R., Rudd, R.E. and Sutton, A.P.: c(8X2) zeta surface.' Physical Review B 69 (12) 'Atomistic modelling of diffusional phase (2004) art. no.-125317. transformations with elastic strain.' Journal Of Physics-Condensed Matter 16 (27) (2004) S2679- Leopoldes, J., Dupuis, A., Bucknall, D.G. and S2697. Yeomans, J.M.: 'Jetting micron-scale droplets onto chemically heterogeneous surfaces.' Langmuir 19 Mason, D.R., Rudd, R.E. and Sutton, A.P.: (23) (2003) 9818-9822. 'Stochastic kinetic Monte Carlo algorithms for long- range Hamiltonians.' Computer Physics Li, Q., Kwong, K.W., Ozkaya, D. and Cockayne, Communications 160 (2) (2004) 140-157. D.J.H.: 'Self-assembled periodical polycrystalline- ZnO/a-C nanolayers on Zn nanowire.' Physical Merino, J.L.O. and Todd, R.I. (2003). Alumina/SiC Review Letters 92 (18) (2004) art. no.-186102. nanocomposites for improved surface finish and wear resistance. Proceedings of the American Liao, X.Z., Zou, J. and Cockayne, D.J.H. (2003). Society for Composites 17th Technical Conference. TEM investigations of the compositions in Kim, C.T.S.a.H., CRC Press / American Society for Ge(Si)/Si(001) quantum dots. Microscopy and Composites: 172. Microanalysis Conference. San Antonio.

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Meyer, R.R., Friedrichs, S., Kirkland, A.I., Sloan, J., Newbery, A.P. and Grant, P.S.: 'Large arc voltage Hutchison, J.L. and Green, M.L.H.: 'A composite fluctuations and droplet formation in electric arc method for the determination of the chirality of wire spraying.' Powder Metallurgy 46 (3) (2003) single walled carbon nanotubes.' Journal Of 229-235. Microscopy-Oxford 212 (2003) 152-157. Nguyen-Manh, D., Cockayne, D.J.H., Doeblinger, Meyer, R.R. and Kirkland, A.I. (2004). Automated M., Marsh, C., Sutton, A.P. and van Duin, A.C.T. Object Wave Restoration from Combined Tilt Focus (2004). Structural modelling of nano-amorphous Si- Series. APEM, Japan Society for Microscopy. O-N films in silicon nitride ceramics. Electron Microscopy And Analysis 2003: 139-142. Meyer, R.R. and Kirkland, A.I. (2004). Measuring isoplanaticity in high-resolution electron Nicholls, R.J., Pankhurst, D.A., Botton, G.A., Lazar, microscopy. Electron Microscopy And Analysis S. and Cockayne, D.J.H. (2004). Energy loss near 2003: 199-202. edge structure study of fullerenes. Electron Microscopy And Analysis 2003: 443-446. Meyer, R.R., Kirkland, A.I., Dovey, M., Cockayne, D.J.H. and Jeffreys, P. (2004). Remote microscopy Nickel, J.H., Tran, L., Portier, X. and Petford-Long, using the grid. Electron Microscopy And Analysis A.K.: 'Control of ferromagnetic coupling by in situ 2003: 173-176. interface modification.' Journal Of Applied Physics 94 (12) (2003) 7687-7691. Meyer, R.R., Kirkland, A.I. and Saxton, W.O.: 'A new method for the determination of the wave O'Reilly, K., Warren, P., Schumacher, P. and aberration function for high-resolution TEM. 2. Cantor, B.: 'Special issue - Eleventh international Measurement of the antisymmetric aberrations.' conference on rapidly quenched and metastable Ultramicroscopy 99 (2-3) (2004) 115-123. materials - Preface.' Materials Science And Engineering A-Structural Materials Properties Mi, J., Harding, R.A., Wickins, M. and Campbell, Microstructure And Processing 375-77 (2004) 1-1. J.: 'Entrained oxide films in TiAl castings.' Intermetallics 11 (4) (2003) 377-385. Oh, J.C. and Lee, S.: 'Correlation of microstructure and abrasive and sliding wear resistance of Mihajlov, A.A., Ignjatovic, L.M., Dimitrijevic, M.S. (TiC,SiC)/Ti-6AI-4V surface composites fabricated and Djuric, Z.: 'Symmetrical chemi-ionization and by high-energy electron-beam irradiation.' chemi-recombination processes in low-temperature Metallurgical And Materials Transactions A- layers of helium-rich DB white dwarf atmospheres.' Physical Metallurgy And Materials Science 35A (1) Astrophysical Journal Supplement Series 147 (2) (2004) 139-151. (2003) 369-377. Oliver, R.A., Kappers, M.J., Rice, J.H., Smith, J.D., Morgan, A.J., Sturzenbaum, S.R., Winters, C., Taylor, R.A., Humphreys, C.J. and Briggs, G.A.D.: Grime, G.W., Abd Aziz, N.A. and Kille, P.: 'Growth of InGaN quantum dots on GaN by 'Differential metallothionein expression in MOPVE, employing a growth temperature nitrogen earthworm (Lumbricus rubellus) tissues.' anneal.' Physica Status Solidi c (2003) 2515-2519. Ecotoxicology And Environmental Safety 57 (1) (2004) 11-19. Ozer, H.O., Norris, A., Oral, A., Hoffmann, P.M. and Pethica, J.B.: 'Low-amplitude, force gradient Mrovec, M., Nguyen-Manh, D., Pettifor, D.G. and imaging of Cu(100) surface using tunnel current Vitek, V.: 'Bond-order potential for molybdenum: feedback.' Nanotechnology 15 (2) (2004) S5-S8. Application to dislocation behavior.' Physical Review B 69 (9) (2004) art. no.-094115. Ozkaya, D., McBride, W. and Cockayne, D.J.H.: 'Radial distribution function analysis of the Mrovec, M., Ochs, T., Elsasser, C., Vitek, V., amorphous barrier layer in magnetic spin tunnel Nguyen-Manh, D. and Pettifor, D.G.: 'Never ending junctions.' Interface Science 12 (2-3) (2004) 321- saga of a simple boundary.' Zeitschrift Fur 325. Metallkunde 94 (3) (2003) 244-249. Pankhurst, D.A., Nguyen-Manh, D. and Pettifor, Nazir, A., Lovett, B.W., Barrett, S.D., Spiller, T.P. D.G.: 'Electronic origin of structural trends across and Briggs, G.A.D.: 'Selective spin coupling early transition- metal disilicides: Anomalous through a single exciton.' Physical Review Letters behavior of CrSi2.' Physical Review B 69 (7) (2004) 93 (2004) 150502. art. no.-075113.

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Park, S.-B., Stone, I.C. and Cantor, B. (2004). Rajta, I., Gomez-Morilla, I., Abraham, M.H. and Rheocasting of Aluminium Alloys. Solidification of Kiss, A.Z.: 'Proton beam micromachining on Aluminium Alloys. Chu, M.G., Granger, D.A. and PMMA, Foturan and CR-39 materials.' Nuclear Han, Q., TMS Warrendale: 257-266. Instruments & Methods In Physics Research Section B- Beam Interactions With Materials And Atoms Petford-Long, A.K., Larson, D.J., Cerezo, A., 210 (2003) 260-265. Portier, X., Shang, P., Ozkaya, D., Long, T. and Clifton, P.H.: 'The role of atomic scale investigation Reddy, B., Doherty, M. and Sykes, J.M.: in the development of nanoscale materials for 'Breakdown of organic coatings in corrosive information storage applications.' Microscopy And environments examined by scanning Kelvin probe Microanalysis 10 (3) (2004) 366-372. and scanning acoustic microscopy.' Electrochimica Acta 49 (17-18) (2004) 2965-2972. Pettifor, D.G.: 'Electron theory in materials modeling.' Acta Materialia 51 (19) (2003) 5649- Rice, J.H., Jajour, A., Taylor, R.A., Oliver, R.A., 5673. Briggs, G.A.D., Kappers, M.J. and Humphreys, C.J.: 'Temporal variation in photoluminescence Pettifor, D.G., Finnis, M.W., Nguyen-Manh, D., from single InGaN quantum dots.' Applied Physics Murdick, D.A., Zhou, X.W. and Wadley, H.N.G.: Letters 84 (2004) 4110-4112. 'Analytic bond-order potentials for multicomponent systems.' Materials Science And Engineering A- Rice, J.H., Oliver, R.A., Robinson, J.W., Smith, Structural Materials Properties Microstructure And J.D., Taylor, R.A., Briggs, G.A.D., Kappers, M.J., Processing 365 (1-2) (2004) 2-13. Humphreys, C.J. and Yasin, S.: 'InGaN quantum dots grown by MOVPE via a droplet epitaxy route.' Pettifor, D.G. and Oleynik, II: 'Interatomic bond- Physica E 21 (2004) 546-550. order potentials and structural prediction.' Progress In Materials Science 49 (3-4) (2004) 285-312. rice, J.H., Robinson, J.W., Jarjour, A., Smith, J.D., Taylor, R.A., Oliver, R.A., Briggs, G.A.D., Philp, E., Sloan, J., Kirkland, A.I., Meyer, R.R., Kappers, M.J. and Humphreys, C.J.: Friedrichs, S., Hutchison, J.L. and Green, M.L.H.: 'Photoluminescence studies of exciton 'An encapsulated helical one-dimensional cobalt recombination and dephasing in single GaInN iodide nanostructure.' Nature Materials 2 (12) quantum dots.' IEEE Transactions on (2003) 788-791. Nanotechnology 3 (2004) 343-347.

Porfyrakis, K. and Assender, H.E.: 'Mesoscale Robinson, J.W., Rice, J.H., Jarjour, A., Smith, J.D., modelling of processing rubber toughened acrylic Taylor, R.A., Oliver, R.A., Briggs, G.A.D., polymers.' Plastic and Rubber Composites (2004) Kappers, M.J., Humphreys, C.J. and Arakawa, Y.: 'Time-resolved dynamics in single InGaN quantum Porfyrakis, K., Britz, D.A., Khlobystov, A.N., dots.' Applied Physics Letters 83 (13) (2003) 2674- Ardavan, A., Briggs, G.A.D., Kanai, M., Nawaz, S. 2676. and Dennis, T.J.S.: 'Endohedral fullerene dimers as potential building blocks for a quantum computer.' Robinson, J.W., Rice, J.H., Jarjour, A., Smith, J.D., Proceedings of the Electrochemical Society 13 Taylor, R.A., Oliver, R.A., Briggs, G.A.D., (2003) 529-537. Kappers, M.J., Humphreys, C.J., Yasin, S. and Arakawa, Y. (2004). Time-integrated and time- Prima, F., Tomut, M., Stone, I., Cantor, B., resolved photoluminescence studies of InGaN Janickonic, D., Vlasak, G. and Svec, P.: 'In situ quantum dots. 8th Conference on optics of excitons resistometric investigation of phase transformations in confined systems. Cingolani, R.: 568-572. in rapidly solidified Al-based alloys containing dispersed nanoscale particles.' Materials Science Sachlos, E. and Czernuszka, J.T. (2004). Collagen- And Engineering A-Structural Materials Properties based scaffolds internal microchannels. 7th World Microstructure And Processing 375-77 (2004) 772- Biomaterials Congress. 775. Sachlos, E. and Czernuszka, J.T. (2004). Controlling Qin, G.W., Oikawa, K., Smith, G.D.W. and Hao, pore size in Collagen Scaffolds. 7th World S.M.: 'Wire electric discharge machining induced Biomaterials Congress. titanium hydride in Ti-46Al-2Cr alloy.' Intermetallics 11 (9) (2003) 907-910. Sachlos, E. and Czernuszka, J.T. (2004). Rapid prototyping of collagen scaffolds. 7th World Biomaterials Congress.

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Sawada, H., Tomita, T., Kaneyama, T., Hosokawa, Sloan, J., Kirkland, A.I., Hutchison, J.L. and Green, F., Naruse, M., Honda, T., Hartel, P., Haider, M., M.L.H.: 'Aspects of crystal growth within carbon Tanaka, N., Hetherington, C.J.D., Doole, R.C., nanotubes.' Comptes Rendus Physique 4 (9) (2003) Kirkland, A.I., Hutchison, J.L., Titchmarsh, J.M. 1063-1074. and Cockayne, D.J.H.: 'Cs corrector for illumination.' Microscopy and Microanalysis 10 Sloan, J., Kirkland, A.I., Hutchison, J.L. and Green, (Suppl 2) (2004) 976. M.L.H. (2003). Integral Atomic Layer Architectures of 1D Crystals Inserted into Single Walled Carbon Sawada, H., Tomita, T., Naruse, M., Honda, T., Nanotubes. Electron MIcroscopy of Nanotubes. Hartel, P., Haider, M., Hetherington, C.J.D., Doole, Wang, Z.L. and Hui, C., Kluwer Press. Ch 12: 273- R.C., Kirkland, A.I., Hutchison, J.L., Titchmarsh, 300. J.M. and Cockayne, D.J.H. (2004). 200kV TEM with Cs correctors for illumination and imaging. Sloan, J., Langley, K.L., Day, E.V., Meyer, R.R. APEM, Japan Society for Microscopy. and Kirkland, A.I. (2004). Studies of variations in insertion cations in Intergrowth Tungsten Bronzes Screen, T.E.O., Thorne, J.R.G., Denning, R.G., (ITBs). Electron Microscopy And Analysis 2003: Bucknall, D.G. and Anderson, H.L.: 'Two methods 71-74. for amplifying the optical nonlinearity of a conjugated porphyrin polymer: transmetallation and Sloan, J., Langley, K.L., Kirkland, A.I., Meyer, self- assembly.' Journal Of Materials Chemistry 13 R.R., Sayagues, M.J., Tilley, R.J.D. and Hutchison, (11) (2003) 2796-2808. J.L. (2004). Structural studies of a modulated quaternary layered perovskite. Electron Microscopy Scruby, L.A., Titchmarsh, J.M. and Jenkins, M.L. And Analysis 2003: 229-232. (2004). The effect of radiation damage on anomalous absorption in the TEM. Electron Sloan, J., Luzzi, D.E., Kirkland, A.I., Hutchison, Microscopy And Analysis 2003: 311-314. J.L. and Green, M.L.H.: 'Imaging and characterization of molecules and one-dimensional Sha, G. and Cerezo, A.: 'Characterization of crystals formed within carbon nanotubes.' Mrs precipitates in an aged 7xxx series Al alloy.' Surface Bulletin 29 (4) (2004) 265-271. And Interface Analysis 36 (5-6) (2004) 564-568. Smit, M.A., Hunter, J.A., Sharman, J.D.B., Sha, G. and Cerezo, A.: 'Early-stage precipitation in Scamans, G.M. and Sykes, J.M.: 'Effects of thermal Al-Zn-Mg-Cu alloy (7050).' Acta Materialia 52 and mechanical treatments on a titanium- based (2004) 4503-4516. conversion coating for aluminium alloys.' Corrosion Science 46 (7) (2004) 1713-1727. Silly, F., Pivetta, M., Ternes, M., Patthey, F., Pelz, J.P. and Schneider, W.D.: 'Coverage-dependent self- Stowe, D.J., Galloway, S.A., Senkader, S., Mallik, organization: from individual adatoms to adatom K., Falster, R.J. and Wilshaw, P.R.: 'Near-band gap superlattices.' New Journal Of Physics 6 (2004) art. luminescence at room temperature from dislocations no.-16. in silicon.' Physica B-Condensed Matter 340 (2003) 710-713. Silly, F., Pivetta, M., Ternes, M., Patthey, F., Pelz, J.P. and Schneider, W.D.: 'Creation of an atomic Stowe, D.J., Galloway, S.A., Senkader, S., Mallik, superlattice by immersing metallic adatoms in a K., Falster, R.J. and Wilshaw, P.R. (2004). A room two-dimensional electron sea.' Physical Review temperature cathodoluminescence study of Letters 92 (1) (2004) art. no.-016101. dislocations in silicon. Electron Microscopy And Analysis 2003: 67-70. Sloan, J., Carter, R., Philp, E., Kirkland, A.I., Meyer, R.R., Hutchison, J.L. and Green, M.L.H. Su, Y.K., Qin, D.H., Zhang, H.L., Li, H. and Li, (2004). Super-resolved imaging of twisted 1D H.L.: 'Microstructure and magnetic properties of crystals formed within single walled carbon bamboo-like CoPt/Pt multilayered nanowire arrays.' nanotubes. Proceedings of the 13th Electron Chemical Physics Letters 388 (4-6) (2004) 406-410. Microscopy Conference. Antwerp, Belgium. 2: 321. Sutton, A.P. and Todorov, T.N.: 'A Maxwell Sloan, J., Kirkland, A.I., Hutchison, J.L., Friedrichs, relation for current-induced forces.' Molecular S. and Green, M.L.H. (2004). Synthesis and Physics 102 (2004) 919-925. Structural Characterisation of Single Wall Carbon Nanotubes Filled with Ionic and Covalent Materials. Suvorov, V.G. and Zubarev, N.M.: 'Formation of Molecular Nanowires and other Quantum Objects. the Taylor cone on the surface of liquid metal in the Alexandrov, A.S., Kluwer Academic Publishers: 77- presence of an electric field.' Journal Of Physics D- 88. Applied Physics 37 (2) (2004) 289-297.

Page 46 Publications

Swaminathan, P., Disley, P.F. and Assender, H.E.: Vlandas, A., Carter, R., Sorsa, S., Flahaut, E., Sloan, 'Surface modification of ion exchange membrane J., Kirkland, A.I., Hutchison, J.L. and Green, using amines.' Journal Of Membrane Science 234 M.L.H. (2004). Encapsulation of semiconductors in (1-2) (2004) 131-137. double wall carbon nanotubes. Proceedings of the 13th Electron Microscopy Conference. Antwerp, Sykes, J.M.: 'A variant of the Brasher-Kingsbury Belgium. 2: 345. equation.' Corrosion Science 46 (3) (2004) 515-517. Vurpillot, F., Cerezo, A., Blavette, D. and Larson, Tanner, B.K., Wu, H.Z., Roberts, S.G. and Hase, D.J.: 'Modeling image distortions in 3DAP.' T.P.A.: 'Subsurface damage in alumina and Microscopy And Microanalysis 10 (3) (2004) 384- alumina-silicon carbide nanocomposites.' 390. Philosophical Magazine 84 (12) (2004) 1219-1232. Vurpillot, F., Larson, D. and Cerezo, A.: Taylor, R.A., Rice, J.H., Jajour, A., Smith, J.D., 'Improvement of multilayer analyses with a three- Oliver, R.A., Briggs, G.A.D., Kappers, M.J., dimensional atom probe.' Surface And Interface Humphreys, C.J. and Arakawa, Y.: 'Dynamics of Analysis 36 (5-6) (2004) 552-558. single InGaN quantum dots.' Physica E 21 (2004) 285-289. Walpole, A.R., Briggs, E.P., Karlsson, M., Palsgard, E. and Wilshaw, P.R.: 'Nano-porous alumina Thamavaranukup, N., Hoppe, H.A., Ruiz-Gonzalez, coatings for improved bone implant interfaces.' L., Costa, P., Sloan, J., Kirkland, A. and Green, Materialwissenschaft Und Werkstofftechnik 34 (12) M.L.H.: 'Single-walled carbon nanotubes filled with (2003) 1064-1068. M OH (M = K, Cs) and then washed and refilled with clusters and molecules.' Chemical Wang, Y.G. and Petford-Long, A.K.: 'Magnetization Communications (15) (2004) 1686-1687. reversal in the pinned layer of CoFe/PtMn bilayers.' Journal Of Magnetism And Magnetic Materials 279 Titchmarsh, J.M., Cockayne, D.J.H., Doole, R.C., (1) (2004) 82-90. Hetherington, C.J.D., Hutchison, J.L., Kirkland, A.I. and Sawada, H. (2004). A versatile double Warburton, P.A., Kuzhakhmetov, A.R., Chana, aberration-corrected, energy filtered HREM/STEM O.S., Burnell, G., Blamire, M.G., Schneidewind, H., for materials science. Proceedings of the 13th Koval, Y., Franz, A., Muller, P., Hyland, D.M.C., Electron Microscopy Conference. Antwerp, Dew-Hughes, D., Wu, H. and Grovenor, C.R.M.: Belgium. 2: 27. 'Josephson fluxon flow and phase diffusion in thin- film intrinsic Josephson junctions.' Journal Of Todd, R.I. (2003). Residual stresses in ceramic Applied Physics 95 (9) (2004) 4941-4948. materials. Analysis of residual stress by diffraction using neutron and synchrotron radiation. Lodini, Warot, B., Imrie, J., Petford-Long, A.K., Nickel, M.E.F.a.A. London, Taylot and Francis: 334-348. J.H. and Anthony, T.C.: 'Influence of seed layers on the microstructure of NiFe layers.' Journal of Todd, R.I. (2005). Alumina-SiC Nanocomposites. Magnetism and Magnetic Materials 272-276 Supp 1 Nanomaterials. Cantor, B. Bristol, Institute of (2004) E1495-E1496. Physics: 220-232. Warot, B., Imrie, J., Petford-Long, A.K., Sharma, Todd, R.I. and Derby, B.: 'Thermal stress induced M. and Anthony, T.C. (2004). Amorphous microcracking in alumina-20% SiCp composites.' ferromagnetic layers for magnetic tunnel junctions. Acta Materialia 52 (6) (2004) 1621-1629. Electron Microscopy And Analysis 2003: 49-52.

Tomut, M., Prima, F., Huenen, G., Vaughan, G., White, R.E., Wade-Martins, R., Hart, S.L., Yavari, A.R., Svec, P., Stone, I.C. and Cantor, B.: Frampton, J., Huey, B., Desai-Mehta, A., 'Microstructure evolution of high strength AlFeVTi Cerosaletti, K.M., Concannon, P. and James, M.R.: nanoquasicrystalline alloys at elevated temperature.' 'Functional delivery of large genomic DNA to Materials Science And Engineering A-Structural human cells with a peptide-lipid vector.' Journal Of Materials Properties Microstructure And Processing Gene Medicine 5 (10) (2003) 883-892. 375-77 (2004) 1239-1245. Wildgoose, G.G., Leventis, H.C., Streeter, I., Trancik, J.E., Czernuszka, J.T. and Bell, F. (2004). Lawrence, N.S., Wilkins, S.J., Jiang, L., Jones, Nanoscale origins of spider dragline mechanical T.G.J. and Compton, R.G.: 'Abrasively immobilised properties. MRS Fall Meeting. multiwalled carbon nanotube agglomerates: A novel electrode material approach for the analytical sensing of pH.' Chemphyschem 5 (5) (2004) 669- 677.

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Wiltshire, J.G., Khlobystov, A.N., Li, L.J., Lyapin, Zhang, H.L., Okayasu, T. and Bucknall, D.G.: S.G., Briggs, G.A.D. and Nicholas, R.J.: 'Large area ordered lateral patterns in confined 'Comparative studies on acid and thermal based polymer thin films.' European Polymer Journal 40 selective purification of HiPCO produced single- (5) (2004) 981-986. walled carbon nanotubes.' Chemical Physics Letters 386 (4-6) (2004) 239-243. Zhou, Z., Dudarev, S.L., Jenkins, M.L. and Sutton, A.P. (2004). A comparison of the column Xie, W.H., Liu, B.G. and Pettifor, D.G.: 'Half- approximation and the Howie-Basinski approach in metallic ferromagnetism in transition metal simulations of TEM images under weak-beam pnictides and chalcogenides with wurtzite structure.' diffraction conditions. Electron Microscopy And Physical Review B 68 (13) (2003) art. no.-134407. Analysis 2003: 203-206.

Yonge, L., Gracheva, S., Wilkins, S.J., Livingstone, Zhou, Z., Dudarev, S.L., Jenkins, M.L., Sutton, A.P. C. and Davis, J.: 'Potentiometric differentiation of and Kirk, M.A.: 'Simulations of electron diffraction mono- and macromolecular thiol within human images of nanometer-sized dislocation loops.' Mat. plasma at carbon fiber electrodes.' Journal Of The Res. Soc. Symp. Proc. 792 (2004) 491. American Chemical Society 126 (25) (2004) 7732- 7733. Zou, J. and Cockayne, D.J.H. (2003). Transmission Electron Microscopy investigations of misfit Zhang, H.L. and Bucknall, D.G.: 'Temperature dislocations in lattice-mismatched semiconductor controlled lateral pattern formation in confined heterostructures. Progress in Transmission Electron polymer thin films.' Chemical Research In Chinese Microscopy 2 - Applications in Materials Science. Universities 20 (4) (2004) 511-515. Zhang, X.-F. and Zhang, Z., Springer.

Zhang, H.L., Bucknall, D.G. and Dupuis, A.: Zou, J., Liao, X.Z., Cockayne, D.J.H. and Jiang, 'Uniform nanoscopic polystyrene patterns produced J.M. (2003). Strain relaxation mechanisms in from a microscopic mold.' Nano Letters 4 (8) (2004) coherent and incoherent Ge(Si)/Si islands. 1513-1519. Microscopy and Microanalysis Conference. San Antonio.

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Page 48 Department of Materials University of Oxford Tel +44 (0)1865 273700 Parks Road Fax +44 (0)1865 273789 Oxford OX1 3PH Email [email protected] United Kingdom Web www.materials.ox.ac.uk