Liquidlike correlations in single-crystalline Y2Mo2O7: An unconventional spin glass

作     者：H. J. Silverstein K. Fritsch F. Flicker A. M. Hallas J. S. Gardner Y. Qiu G. Ehlers A. T. Savici Z. Yamani K. A. Ross B. D. Gaulin M. J. P. Gingras J. A. M. Paddison K. Foyevtsova R. Valenti F. Hawthorne C. R. Wiebe H. D. Zhou 

作者机构：Department of Chemistry University of Manitoba Winnipeg Manitoba R3T 2N2 Canada Department of Physics and Astronomy McMaster University Hamilton Ontario L8S 4M1 Canada Department of Physics and Astronomy University of Waterloo Waterloo Ontario N2L 3G1 Canada Perimeter Institute for Theoretical Physics 31 Caroline Street North Waterloo Ontario N2L 2Y5 Canada School of Physics HH Wills Physics Laboratory University of Bristol Bristol BS8 1TL United Kingdom Indiana University 2401 Milo B. Sampson Lane Bloomington Indiana 47408 USA NIST Center for Neutron Research National Institute of Standards and Technology Gaithersburg Maryland 20899-6102 USA Department of Materials Science and Engineering University of Maryland College Park Maryland 20742 USA Quantum Condensed Matter Division Neutron Sciences Directorate Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Neutron Data Analysis and Visualization Division Neutron Sciences Directorate Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Canadian Neutron Beam Centre Chalk River Ontario K0J 1P0 Canada Canadian Institute for Advanced Research 180 Dundas St. W. Toronto Ontario M5G 1Z8 Canada Brockhouse Institute for Materials Research McMaster University Hamilton Ontario L8S 4M1 Canada Department of Chemistry University of Oxford Inorganic Chemistry Laboratory South Parks Road Oxford OX1 3QR United Kingdom ISIS Facility Rutherford Appleton Laboratory Chilton Didcot Oxfordshire OX11 0QX United Kingdom Institut für Theoretische Physik Goethe-Universität Frankfurt Frankfurt am Main 60438 Germany Department of Geological Sciences University of Manitoba Winnipeg Manitoba R3T 2N2 Canada Department of Chemistry University of Winnipeg 515 Portage Ave. Winnipeg Manitoba R3B 2E9 Canada Department of Physics and Astronomy University of Tennessee Knoxville Tennessee 37996-1200 USA National High Magnetic Field Laboratory Florida State University Tallahassee Florida 32306-4005 USA 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2014年第89卷第5期

页      面：054433-054433页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：Engineering and Physical Sciences Research Council, EPSRC, (EP/G004528/2) Engineering and Physical Sciences Research Council, EPSRC 

主　　题：SPIN glasses SINGLE crystals X-ray powder diffraction LATTICE theory NEUTRON scattering ISOTROPIC properties HAMILTONIAN systems 

摘      要：The spin-glass behavior of Y2Mo2O7 has remained a puzzle for nearly three decades. Free of bulk disorder within the resolution of powder diffraction methods, it is thought that this material is a rare realization of a spin glass resulting from weak disorder such as bond disorder or local lattice distortions. Here we report on the single-crystal growth of Y2Mo2O7. Using neutron scattering, we present isotropic magnetic diffuse scattering occurring below the spin-glass transition. Our attempts to model the diffuse scattering using a computationally exhaustive search of a class of simple spin Hamiltonians show no agreement with the experimentally observed energy-integrated (diffuse) neutron scattering. This suggests that spin degrees of freedom are insufficient to describe this system. Indeed, a T2 temperature dependence in the heat capacity and density functional theory calculations hint at the presence of a significant frozen degeneracy in both the spin and orbital degrees of freedom resulting from spin-orbital coupling (Kugel-Khomskii type) and random fluctuations in the Mo environment at the local level.