Collective excitations in a melt of fast phase change material GeCu2Te3

M Inui; S Hosokawa; S Tsutsui; Y Nakajima; K Matsuda; K Maruyama; A Q R Baron

doi:10.1088/1361-648X/acc2ff

Collective excitations in a melt of fast phase change material GeCu₂Te₃

J Phys Condens Matter. 2023 Mar 29;35(23). doi: 10.1088/1361-648X/acc2ff.

Authors

M Inui¹, S Hosokawa², S Tsutsui³, Y Nakajima⁴, K Matsuda⁴, K Maruyama⁵, A Q R Baron^{3

6}

Affiliations

¹ Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521, Japan.
² Institute of Industrial Nanomaterials, Kumamoto University, Kumamoto 860-8555, Japan.
³ Japan Synchrotron Radiation Research Institute (JASRI), Sayo-cho, Hyogo 679-5198, Japan.
⁴ Department of Physics, Kumamoto University, Kumamoto 860-8555, Japan.
⁵ Faculty of Science, Niigata University, Niigata 950-2181, Japan.
⁶ Materials Dynamics Laboratory, RIKEN SPring-8 Center, Sayo-cho, Hyogo 679-5148, Japan.

PMID: 36893472
DOI: 10.1088/1361-648X/acc2ff

Abstract

Inelastic x-ray scattering measurements have been carried out to investigate atomic dynamics in a melt of fast phase change material GeCu₂Te₃. The dynamic structure factor was analysed using the model function with three damped harmonic oscillator components. By investigating the correlation between the excitation energy and the linewidth, and that between the excitation energy and the intensity on contour maps of a relative approximate probability distribution function proportional toexp(-χ2/N), we could judge the reliability of each inelastic excitation in the dynamic structure factor. The results indicate that there are two inelastic excitation modes besides the longitudinal acoustic one in the liquid. The lower energy excitation could be assigned to the transverse acoustic one whereas the higher energy one disperses like fast sound. The latter result may imply that the liquid ternary alloy exhibits a microscopic phase separation tendency.

Keywords: atomic dynamics; fast phase change material; fast sound; inelastic x-ray scattering; liquid GeCu2Te3; transverse acoustic mode.