Phase diagram and equation of state of TiH at high pressures and high temperatures

高温高圧下におけるTiHの状態図と状態方程式

遠藤 成輝; 齋藤 寛之; 町田 晃彦; 片山 芳則; 青木 勝敏

Endo, Naruki; Saito, Hiroyuki; Machida, Akihiko; Katayama, Yoshinori; Aoki, Katsutoshi

In the present study, we clearly determined the phase diagram of TiH at high pressures and high temperatures, and were the first to report the equation of state (EoS) of TiH with an fcc phase. Compression induced strain inhibited the phase transition from the low-temperature bct phase to the high-temperature fcc phase, making the phase diagram difficult to determine. Thus, the phase boundary was appropriately determined using a sample which was treated at high temperature to remove strain. The obtained phase boundary was considerably lower than the experimental data reported by Vennila et al (2008). Additionally, we successfully obtained the high temperature Birch-Murnaghan EoS of TiH, and reported the thermoelastic parameters of fcc TiH.