@article{83e2ce69d4434200b77d49bb9dd8d99e,
title = "Physical insights on the low lattice thermal conductivity of AgInSe2",
abstract = "Uncovering the microscopic mechanism of low lattice thermal conductivity is essential for exploration and design of high-performance thermoelectrics. AgInSe2 exhibits high thermoelectric performance mainly due to its low thermal conductivity. Here, the origin of its intrinsic low lattice thermal conductivity is studied by temperature-dependent inelastic neutron scattering (INS), X-ray absorption fine structure (XAFS) spectra measurements, and first-principles calculations. A prominent “avoided crossing” feature and low-lying optical modes in the phonon dispersion of AgInSe2 are observed experimentally. These lattice dynamical features cause a local reduction of the phonon group velocity and strongly scatter heat-carrying acoustic phonons, contributing to its intrinsic low lattice thermal conductivity. In addition, both temperature-dependent phonon dispersions and phonon density-of-states measurements reveal strong anharmonicity or phonon-phonon interactions in AgInSe2. XAFS and phonon eigenvector analysis demonstrate the dominant role of Ag vibrations, which is closely associated with the “avoided crossing”, low-lying optical modes and large structural distortion, and thus dominates the reduction of lattice thermal conductivity of AgInSe2.",
keywords = "Avoided crossing, Inelastic neutron scattering, Phonon, Thermal transport, X-ray absorption fine structure",
author = "Yingcai Zhu and Bin Wei and Junyan Liu and Koocher, {Nathan Z.} and Yongheng Li and Lei Hu and Wenke He and Guochu Deng and Wei Xu and Xueyun Wang and Rondinelli, {James M.} and Zhao, {Li Dong} and Snyder, {G. Jeffrey} and Jiawang Hong",
note = "Funding Information: This work is supported by the National Science Foundation of China (Grant No. 11572040 and 11604011), Beijing Natural Science Foundation (Grant No. Z190011) and the technological Innovation Project of Beijing Institute of technology. Theoretical calculations were undertaken using resources of the National Supercomputer Center in Guangzhou. G. J. S. acknowledges NSF DMREF award (1729487) for support. Computational work at Northwestern was supported by the National Science Foundation's (NSF) MRSEC program (DMR-1720139) at the Materials Research Center of Northwestern University. We acknowledge all of beamline scientists at the SIKA at the Australia nuclear science and technology organization, the ARCS time-of-fight chopper spectrometer at the Spallation Neutron Source at Oak Ridge National Laboratory, and the BM-20-B beamline at advanced photon source in Argonne National Laboratory. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Funding Information: This work is supported by the National Science Foundation of China (Grant No. 11572040 and 11604011 ), Beijing Natural Science Foundation (Grant No. Z190011 ) and the technological Innovation Project of Beijing Institute of technology. Theoretical calculations were undertaken using resources of the National Supercomputer Center in Guangzhou. G. J. S. acknowledges NSF DMREF award ( 1729487 ) for support. Computational work at Northwestern was supported by the National Science Foundation's (NSF) MRSEC program ( DMR-1720139 ) at the Materials Research Center of Northwestern University. We acknowledge all of beamline scientists at the SIKA at the Australia nuclear science and technology organization, the ARCS time-of-fight chopper spectrometer at the Spallation Neutron Source at Oak Ridge National Laboratory, and the BM-20-B beamline at advanced photon source in Argonne National Laboratory. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility, operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357 . Publisher Copyright: {\textcopyright} 2021 Elsevier Ltd",
year = "2021",
month = jul,
doi = "10.1016/j.mtphys.2021.100428",
language = "English (US)",
volume = "19",
journal = "Materials Today Physics",
issn = "2542-5293",
publisher = "Elsevier Ltd",
}