Static and dynamic structures of liquid Ba8Ga16Sn30: a melt of the thermoelectric clathrate compounds. (18th October 2018)

• Record Type: Journal Article
• Authors: Inui, M; Suekuni, K; Kajihara, Y; Hosokawa, S; Takabatake, T; Nakajima, Y; Matsuda, K; Ohara, K; Uchiyama, H; Tsutsui, S
• Is Part Of: Journal of physics. Volume 30:Number 45(2018)
• Publication Date: 2018-10-18
• Subjects: x-ray diffraction -- inelastic x-ray scattering -- structure factor -- dynamic structure factor -- liquid Ba8Ga16Sn30 -- thermoelectric clathrate; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aae3f3
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: X-ray diffraction and inelastic x-ray scattering measurements of liquid Ba8 Ga16 Sn30 have been carried out to investigate local structure and atomic dynamics in the liquid. The pair distribution function shows shorter and longer interatomic distances in the first coordination shell. The dynamic structure factor exhibits the inelastic excitations on both sides of the quasielastic central peak. The inelastic excitations disperse with increasing the momentum transfer, suggesting the longitudinal acoustic mode. We found a low energy excitation in addition to the longitudinal acoustic excitation in the dynamic structure factor and it reminds us a strong relationship with a rattling motion of a guest (Ba) atom in the solid state. The temperature dependence of the pair distribution function and the longitudinal acoustic excitation energy is very weak in a range from 600 to 900 °C. The result suggests that Ba and other atoms in the melt are located around minimum positions of the effective pair potential approximated as a harmonic one.