TY - JOUR
T1 - Peculiar atomic dynamics in liquid GeTe with asymmetrical bonding
T2 - Observation by inelastic x-ray scattering
AU - Inui, M.
AU - Koura, A.
AU - Kajihara, Y.
AU - Hosokawa, S.
AU - Chiba, A.
AU - Kimura, K.
AU - Shimojo, F.
AU - Tsutsui, S.
AU - Baron, A. Q.R.
N1 - Funding Information:
The authors would like to thank S. Kohara for supplying data of liquid GeTe and valuable discussion. The authors would like to acknowledge Japan Society for the Promotion of Science (JSPS) for a Grant-in-Aid for Scientific Research for a Grant-in-Aid for Scientific Research (A) (Grant No. 20244061) and (B) (Grant No. 23340106). The synchrotron radiation experiments were performed at the SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposals No. 2013B1269, No. 2013B1268, and No. 2012A1354).
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/5/14
Y1 - 2018/5/14
N2 - Collective dynamics in liquid GeTe was investigated by inelastic x-ray scattering at 2≤Q≤31nm-1. The dynamic structure factor shows clear inelastic excitations. The excitation energies at low Q disperse with increasing Q, consistent with the behavior of a longitudinal-acoustic excitation. The dispersion curve has a flat-topped region around the pseudo-Brillouin-zone boundary, similar to what is observed in liquid Bi [Inui, Phys. Rev. B 92, 054206 (2015)PRBMDO1098-012110.1103/PhysRevB.92.054206]. The dynamic structure factor shows a low-frequency excitation, and its coupling with the longitudinal-acoustic mode plays an important role for a flat-topped dispersion. From these results, it is inferred that atomic dynamics in liquid GeTe is strongly affected by a Peierls distortion similar to liquid Bi. By comparing the momentum transfer dependence of the excitation energy and quasielastic linewidth to partial structure factors obtained by our own ab initio molecular dynamics simulation for liquid GeTe, the quasielastic and inelastic components were found to be correlated with Te-Te and Ge-(Ge,Te) partial structure factors, respectively.
AB - Collective dynamics in liquid GeTe was investigated by inelastic x-ray scattering at 2≤Q≤31nm-1. The dynamic structure factor shows clear inelastic excitations. The excitation energies at low Q disperse with increasing Q, consistent with the behavior of a longitudinal-acoustic excitation. The dispersion curve has a flat-topped region around the pseudo-Brillouin-zone boundary, similar to what is observed in liquid Bi [Inui, Phys. Rev. B 92, 054206 (2015)PRBMDO1098-012110.1103/PhysRevB.92.054206]. The dynamic structure factor shows a low-frequency excitation, and its coupling with the longitudinal-acoustic mode plays an important role for a flat-topped dispersion. From these results, it is inferred that atomic dynamics in liquid GeTe is strongly affected by a Peierls distortion similar to liquid Bi. By comparing the momentum transfer dependence of the excitation energy and quasielastic linewidth to partial structure factors obtained by our own ab initio molecular dynamics simulation for liquid GeTe, the quasielastic and inelastic components were found to be correlated with Te-Te and Ge-(Ge,Te) partial structure factors, respectively.
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U2 - 10.1103/PhysRevB.97.174203
DO - 10.1103/PhysRevB.97.174203
M3 - Article
AN - SCOPUS:85047263774
SN - 2469-9950
VL - 97
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
IS - 17
M1 - 174203
ER -