LO-mode phonon of KCl and NaCl at 300 K by inelastic x-ray scattering measurements and first principles calculations

Atsushi Togo; Hiroyuki Hayashi; Terumasa Tadano; Satoshi Tsutsui; Isao Tanaka

doi:10.1088/1361-648X/ac7b01

LO-mode phonon of KCl and NaCl at 300 K by inelastic x-ray scattering measurements and first principles calculations

J Phys Condens Matter. 2022 Jul 1;34(36). doi: 10.1088/1361-648X/ac7b01.

Authors

Atsushi Togo^{1

2}, Hiroyuki Hayashi³, Terumasa Tadano⁴, Satoshi Tsutsui^{5

6}, Isao Tanaka^{2

3

7}

Affiliations

¹ Research and Services Division of Materials Data and Integrated System, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan.
² Center for Elements Strategy Initiative for Structural Materials, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
³ Department of Materials Science and Engineering, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
⁴ Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan.
⁵ Japan Synchrotron Radiation Research Institute, Sayo-cho, Hyogo 679-5198, Japan.
⁶ Institute of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan.
⁷ Nanostructures Research Laboratory, Japan Fine Ceramics Center, Atsuta, Nagoya 456-8587, Japan.

PMID: 35728792
DOI: 10.1088/1361-648X/ac7b01

Abstract

Longitudinal-optical (LO) mode phonon branches of KCl and NaCl were measured using inelastic x-ray scattering (IXS) at 300 K and calculated by the first-principles phonon calculation with the stochastic self-consistent harmonic approximation. Spectral shapes of the IXS measurements and calculated spectral functions agreed well. We analyzed the calculated spectral functions that provide higher resolutions of the spectra than the IXS measurements. Due to strong anharmonicity, the spectral functions of these phonon branches have several peaks and the LO modes along Γ-L paths are disconnected.

Keywords: KCl; NaCl; anharmonicity; inelastic x-ray scattering; phonon calculation.

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