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Neutron Scattering Principal Investigators’ Meeting July 22-25, 2012 Gaithersburg Marriott Washingtonian Center Gaithersburg, Maryland Office of Basic Energy Sciences Division of Materials Sciences and Engineering On the Cover Top Left: Predicted density vs. temperature phase diagram of supercooled water in the presence of a first- order high density liquid (HDL) to low density liquid (LDL) phase transition based on the measured densities of confined water at high pressures during heating (the red curve connecting the points) and cooling (the blue curve connecting the points) cycles. The presence of significant hysteresis at high pressures in the measured densities during heating and cooling scans when crossing the transition line points to the putative first order liquid-liquid transition. However, at relatively low pressures, when no first-order line is crossed, there should be no hysteresis as shown with the green curve. (Yang Zhang, Antonio Faraone, W. A. Kamitakahara, Kao-Hsiang Liu, Chung-Yuan Mou, Juscelino B. Leão, Sung Chang, and Sow-Hsin Chen, Density hysteresis of heavy water confined in a nanoporous silica matrix, Proc. National Academy of Sciences, 2011, 108, 12206) Top Middle: A) The fundamental building block of the copper-oxide superconductors is the Cu-O sheet. The well-studied conventional magnetism results from localized spin moments on the Cu atoms. B) Proposed novel magnetism due to circulating charge currents. C) Intensity of scattered neutrons at four wave vectors for the model material HgBa2CuO4+δ. Two magnetic excitations (waves) can be discerned, one at about 40 meV and another at about 55 meV. (Yuan Li, G. Yu, M. K. Chan, V. Balédent, Yangmu Li, N. Bariši´c, X. Zhao, K. Hradil, R. A. Mole, Y. Sidis, P. Steffens, P. Bourges, and M. Greven, Nature Physics, 2012, 8, 404–410) Top Right: The spectrum of low-energy magnetic excitations in an Fe-based superconductor is found to evolve in an unusual way. Contour intensity maps showing the fitted magnetic scattering intensity versus ħω and Q at different temperatures for the superconducting FeTe0.35Se0.65: (a) 4 K, (b) 25 K, (c) 100 K, and (d) 300 K. The change in the distribution of spectral weight between 4 K and 25 K is due to the superconducting transition. The robust spectral weight at all temperatures cannot be explained by conduction electrons alone. (Zhijun Xu, Jinsheng Wen, Guangyong Xu, Songxue Chi, Wei Ku, Genda Gu, and J. M. Tranquada, Phys. Rev. B, 2011, 84, 052506) Bottom Left: Small-angle neutron scattering from a bulk sample of Ni44Co6Mn40Sn10, a precisely engineered off-stoichiometric Heusler alloy, showing the 2D qx-qy small angle scattering intensity map in a strained sample. (Bhatti, El-Khatib, Srivastava, James, and Leighton, Phys. Rev. B, 2012, 85, 134450) Bottom Middle: Frozen phonon calculations evidencing that the most anomalous modes are quantum quartic oscillators, with transverse motions of fluorine atoms – a new mechanism for the negative thermal expansion coefficient of scandium fluoride. (Chen W. Li, Xiaoli Tang, J. A. Muñoz, J. B. Keith, S. J. Tracy, D. L. Abernathy, and B. Fultz, Physical Review Letters, 2011, 107, 195504) Bottom Right: (a) Crystal structure of the ideal kagome lattice compound ZnCu3(OH)6Cl2, also called herbertsmithite. (b) Single crystal synthesized for the magnetic measurements. (T.H. Han, S. Chu, and Y.S. Lee, Physical Review Letters, 2012, 108, 157202) This document was produced under contract number DE-AC05-06OR23100 between the U.S. Department of Energy and Oak Ridge Associated Universities. The research grants and contracts described in this document are supported by the U.S. DOE Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. Foreword This volume comprises the scientific content of the 2012 Neutron Scattering Principal Investigators' (PI) Meeting sponsored by the Division of Materials Sciences and Engineering (MSED) in the Office of Basic Energy Sciences (BES) of the U.S. Department of Energy (DOE). This meeting on July 22–25, 2012 at the Gaithersburg Marriott Washingtonian Center in Gaithersburg, Maryland, is the third in the series, covering the projects funded by the Neutron Scattering Program. BES MSED has a long tradition of supporting a comprehensive neutron scattering program in recognition of the high impact neutron scattering and spectroscopy tools have in discovery and use-inspired research. The MSED Neutron Scattering Core Research Activity (CRA) supports basic research on the fundamental interactions of neutrons with matter to achieve an understanding of the atomic, electronic, and magnetic structures and excitations of materials and their relationship to materials’ properties. Major emphasis is on the application of neutron scattering and spectroscopy for materials research, primarily at BES-supported user facilities. Development of next-generation instrumentation concepts, innovative optics for time-of-flight instruments and application of polarized neutrons are distinct aspects of this activity. The increasing complexity of DOE mission-relevant materials for various energy applications requires sophisticated scattering and computational tools to investigate the structure and dynamics at relevant length and time scales. Additionally, neutrons allow access to the behavior of matter in extreme environment such as high temperature, pressure and magnetic field. A continuing theme of this program is the integration of material synthesis, neutron scattering measurements and computational modeling as this is vital to obtain controlled samples for experiments and modeling for an in-depth understanding of the structure and dynamics of materials and their relationship to macroscopic properties. The purpose of the BES biannual PI meetings is to bring together all the researchers funded by BES in the neutron scattering area to get a first-hand look at the range of research topics and ongoing activities in the program, to foster an awareness of the research of others in the program, to facilitate the exchange of new results and research highlights, to promote new ideas and collaborations among participants and BES scientific user facilities, and to identify and pursue new scientific opportunities and new frontiers. For BES the PI meetings provide an opportunity to see the entire portfolio/program at one time on a periodic basis, to assess the state of the program and chart new scientific directions, and to turn a 'collection of projects' into a visionary, forward-looking program. We thank all the meeting participants for their active contributions in sharing their ideas and research accomplishments. Sincere thanks are also due to the speakers from other BES programs involved with neutron scattering in multidisciplinary research. We wish to thank Teresa Crockett in MSED and Lee-Ann Talley at the Oak Ridge Institute for Science and Education (ORISE) for their outstanding work in all aspects of the meeting organization. Thiyaga P. Thiyagarajan and Helen Kerch MSED, BES, Office of Science U.S. Department of Energy i ii Table of Contents Foreword ......................................................................................................................................... i Table of Contents ......................................................................................................................... iii Agenda .......................................................................................................................................... ix Session I: High Temperature Superconductors – Cuprates Neutron Scattering Studies of Cuprate Superconductors J. M. Tranquada, G. D. Gu, M. Hücker, G. Y. Xu, and I. A. Zaliznyak ....................................2 Crystal Growth and Scattering Studies of Model Cuprate Superconductors M. Greven .................................................................................................................................6 Neutron and X-ray Scattering Investigation of Electron-Phonon Effects in Cuprate Superconductors and Related Compounds Dmitry Reznik .........................................................................................................................10 Session II: Correlated Electron Systems (I) Quantum Correlated Materials and Phenomena C. Broholm, N. P. Armitage, R. J. Cava, T. M. McQueen, O. Tchernyshyov, and Z. Tesanovic ....................................................................................................................16 Correlations and Competition between the Lattice, Electrons, and Magnetism R. J. McQueeney, V. P. Antropov, A. I. Goldman, B. N. Harmon, A. Kreyssig, D. Vaknin, and J. L. Zarestky .................................................................................................23 Using Neutron as a Probe to Study Magnetic Excitations in Strongly Correlated Electron Materials Pengcheng Dai ........................................................................................................................31 Phase Competition in Bulk Materials: Superconductivity vs Spin and Charge Density Waves R. Osborn, S. Rosenkranz, O. Chmaissem, S. Avci, J.-P. Castellan, and F. Weber ..............36 Session III: Correlated Electron Systems (II) Complex Electronic Materials J. D. Thompson, E. D. Bauer, M. Janoschek, R. Movshovich, F. Ronning, and H. Yasuoka .......................................................................................................................42 iii Neutron Scattering Studies of Fe-Based Superconductors
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