Scientific Report 2007
Total Page:16
File Type:pdf, Size:1020Kb
Scientific Report 2007 Institut für Festkörperforschung Institute of Solid State Research IFF Scientific Report 2007 Mitglied der Helmholtz-Gemeinschaft Imprint Published by: 2 I 3 Forschungszentrum Jülich GmbH Institut für Festkörperforschung (IFF) 52425 Jülich, Germany Phone: +49 2461 61-4465 Fax: +49 2461 61-2410 E-mail: [email protected] Internet: www.fz-juelich.de/iff/e_iff Conception and Editorial: Angela Wenzik Claus M. Schneider (IFF) Design and Graphics: Clarissa Reisen Dieter Laufenberg (Graphic Department) Homochiral magnetic order in a one-atomic layer thick film of Mn atoms on a W(110) surface. The local magnetic moments at Mn atoms shown as red and green arrows are aligned antiferromagnetically between nearest-neighbor Layout Research Reports: atoms. Superimposed is a spiral pattern of unirotational direction. Ursula Funk-Kath The top picture shows a left-rotating cycloidal spiral, which was found in nature. The bottom picture shows the Dorothea Henkel mirror image, a right rotating spiral, which does not exist. The work results from a collaboration between the IFF Liane Schätzler and the Institute of Applied Physics at the University of Hamburg. The results have been published in Nature 447, Kurt Wingerath p190 (2007). (IFF) Pictures: Forschungszentrum Jülich 266 I 267 except otherwise noted Print: Medienhaus Plump GmbH Rheinbreitbach IFF Scientific Report 2007 • Imprint 2 I 3 Scientific Report 2007 Institut für Festkörperforschung Institute of Solid State Research Contents Foreword page 8 4 I 5 Snapshots 2007 page 10 Awards, Honours, Scholarships page 15 Institute of Solid State Research – Institut für Festkörperforschung (IFF) page 16 HGF Research Programme Condensed Matter Physics page 30 Research Reports Commensurate and Incommensurate Charge Order in Fe2OBO3 page 32 Orbital Fluctuations in the Different Phases of LaVO3 and YVO3 page 34 Quantum Phase Transition in the Two-Band Hubbard Model page 36 Effect of Orbital Degrees of Freedom on the Doping-Driven Mott Transition in La1-xSrxTiO3 page 38 First-Principles Simulation Code Based on Real-Space Method page 40 Image Potential and Field States at Transition Metal Surfaces page 42 The Fe/MgO Interface: The Important Role of Oxygen page 44 Electronic Properties of Individual Point Defects at Semiconductor Surfaces page 46 Trends of Exchange Interactions in Dilute Magnetic Semiconductors page 48 Dumbbell Rattling in Thermoelectric Zinc-Antimony page 50 Flipping Magnetic Vortex Cores on the Picosecond Time Scale page 52 Three-Dimensional Magnetic Normal Modes in Mesoscopic Permalloy Prisms page 54 Breakdown of the Macrospin Picture in Magnetodynamics from Spin Valves page 56 Brillouin Light Scattering from Multilayers with Noncollinear Spin Configuration page 58 Novel Type of Metadislocation in the Complex Metallic Alloy Al-Pd-Fe page 60 Physical Properties of the Complex Metallic Alloy -Al3Mg2 page 62 Instability of a Homogeneous State of a Dilute Bose Gas Upon Cooling page 64 Quasi-Localized Vibrations, Boson Peak and Tunneling in Glasses page 66 Crack Propagation as a Free Boundary Problem page 68 Influence of Strain on the Kinetics of Phase Transitions in Solids page 70 Tomographic Reconstruction and Reduction of Measuring Points in Fuel Cells page 72 Optical Stability of Ultra-High Resolution Transmission Electron Microscopes page 74 Advances in Applied Aberration Corrected HRTEM of Solids page 76 Atomic Structure of -phase Tantalum Nanocrystallites page 78 Contrast Transfer and Resolution Limits for Sub-Angstrom High-Resolution TEM page 80 Quantitative Aberration-Corrected HRTEM of Grain Boundaries in YBCO page 82 Dislocations in SrTiO3 Single Crystals as Potential Easy Diffusion Pathways for SrO-Complexes and Oxygen page 84 Ab Initio Modeling of Atomic Force Microscopy: Benzene On Cu(110) page 86 Charge Transfer in a Molecular Alloy Measured by CH3 Rotational Tunneling page 88 Velocity Selection Problem in the Presence of the Triple Junction page 90 Contents • IFF Scientific Report 2007 Contact Mechanics: Relation Between Interfacial Separation and Load page 92 Dynamics of Argon in Reduced Dimensionality page 94 4 I 5 Hydrodynamic Screening of Star Polymers in Shear Flow page 96 Diffusion and Rheology of Charged Colloids and Bio-Macromolecules page 98 Thermal-Diffusive Behavior of a Dilute Solution of Charged Colloids page 100 SANS Study of Polymer-Linked Droplets page 102 Enhanced Slowing Down of the Colloidal Near Wall Dynamics in a Suspension of Rods page 104 Effect of Polydispersity on Depletion Interaction page 106 Biological Nanomachines page 108 Structure of Interacting Aggregates of Silica Nanoparticles in a Polymer Matrix as Determined from SANS page 110 Tracer-Sphere Diffusion in Rod-Networks page 112 Red Blood Cells: Fluctuations of Coupled Fluid and Solid Membranes page 114 Dynamics of Glass-Forming Materials in Nanoscopic Confinement page 116 On the Interpretation of Dielectric Data in Molecular Glass Formers page 118 Synthesis of Hydrophobic Polyalkylene Oxides and Amphiphilic Polyalkylene Oxide page 120 Nucleation and Growth of CaCO3 Mediated by the Egg-White Protein Ovalbumin page 122 Relevance of Angular Momentum Conservation in Fluid Simulations page 124 Diffusion and Segmental Dynamics of Double-Stranded DNA page 126 Swinging and Tumbling of Fluid Vesicles in Shear Flow page 128 Do Intra-Molecular Relaxations Influence the Damping of Longitudinal Phonons? page 130 Boundary-Induced Phase Transition in Single-File Diffusion page 132 HGF Research Programme Information Technology with Nanoelectronic Systems page 134 Research Reports Surface-, Edge- and Quantum-Well-States of Thin Bi Films for Spintronics page 136 Prediction of High Curie Temperature in bcc-Co and FeCo Alloys page 138 Large Inverse TMR in Co2Cr0.6Fe0.4Al based magnetic tunnel junctions page 140 Electric Switching of Magnetic Vortex Cores in Nanodisks page 142 Asymmetric Spin-Transfer Torque in Single-Crystalline Fe/Ag/Fe Nanopillars page 144 Photon-Assisted Tunneling in a Carbon Nanotube Quantum Dot page 146 Quantum Transport Through Single-Molecule Magnets: Berry-Phase Interference page 148 Superconducting Spintronics: Josephson Junctions with Tailored Ferromagnetic Barrier page 150 Dephasing of a Qubit Via Interaction With a Gate Electrode page 152 THz Josephson Spectroscopy of Optical Phonons in [100]-Tilt Bicrystal Junctions page 154 Thick Epitaxial YBa2Cu3O7-x Films for High-Tc Quantum Interferometers page 156 Nanoscale Phase Transitions in Phase Change Materials page 158 Pb(Zr, Ti)O3 Thin Films on 3D-Capacitor Structures for FeRAM Applications Grown by a LI-ALD Method page 160 Conductive Oxygen Diffusion Barrier for High- Oxide Materials on Silicon Electrodes page 162 Evolution of the Resistive Switching Characteristics During Electroforming of Epitaxial Iron-Doped SrTiO3 Thin Films page 164 Resistive Switching in Ag-Ge-Se and Cu-SiO2 With Extremely Low Write Currents page 166 IFF Scientific Report 2007 • Contents Realization of Self-Assembled Arrays of Nanoscale Resistive Switching Blocks in 6 I 7 Thin Films of Nb-doped SrTiO3 page 168 Effect of Oxygen Ambient on the Bipolar Resistive Switching of Pt/TiO2/Pt page 170 Low Current Resistance Switching in WO3 Thin Films for Non-Volatile Memory Application page 172 Resistance Switching of Atomic Layer Deposited (ALD) TiOx Thin Films page 174 Unit-Cell Scale Mapping of Ferroelectricity in Epitaxial Ferroelectric Films page 176 Elastic Stabilization of Single-Domain Ferroelectric State in Nanoscale Capacitors and Tunnel Junctions page 178 Direct Electrical Characterization of Embedded Ferroelectric Lead Titanate Nanoislands page 180 Polarization and Lattice Strains in Epitaxial BaTiO3 Films Grown by High-Pressure Sputtering page 182 Microstructural Investigation of SrTiO3/BaZrO3 Bilayer Thin Films on MgO Substrates by Means of HRTEM page 184 Self-Assembly of Mixed Monolayers of Mercaptoalkylferrocenes for Nanoscale Surface Patterning page 186 First-Principles Investigation of Terephthalic Acid on Cu(110) page 188 Post Processes for Bioelectronic CMOS Devices page 190 UV-Nanoimprint Lithography with Polymer Molds page 192 Crossbar Array Architectures With Embedded Bottom Electrodes Fabricated with UV Nanoimprint Lithography page 194 Integration of TiO2 into Nano-Crossbar Arrays With 100 nm Half Pitch for Resistive RAM Applications page 196 HGF Research Programme Large-Scale Facilities for Research with Photons, Neutrons and Ions page 198 Research Reports SPHERES: First Productive Experiments page 200 KWS-2 Small-Angle Neutron Diffractometer of JCNS at FRM II page 202 Superconducting Solenoids for the NSE Spectrometer at the SNS page 204 TOPAS Getting on Stage page 206 POWTEX: BMBF-Funding Granted for the High Intensity TOF Diffractometer page 208 Progress on SEOP Development and First Ideas for Onbeam-SEOP page 210 DNS – An Instrument for Unraveling Complex Magnetic Correlations Via Polarization Analysis page 212 Commissioning of the Very Small Angle Neutron Scattering Instrument KWS-3 page 214 The Polarizing Guide System for the J-NSE Spectrometer at the FRM II page 216 Status of the New Reflectometer of JCNS at the FRM II: MARIA page 218 Appendix page 220 Imprint page 267 Contents • IFF Scientific Report 2007 6 I 7 Directors of the Institute of Solid State Research (IFF) from left: Prof. Dr. Jan K. G. Dhont (IFF-7: Soft Condensed Matter) Prof. Dr. Knut Urban (IFF-8: Microstructure Research Prof. Dr. Heiner Müller-Krumbhaar (IFF-3: Theory of Structure Formation) Prof. Dr. Dieter Richter (IFF-5: Neutron Scattering)