Precise structural analyses of advanced materials under high-pressure and high-temperature

Yoshiasa, Akira*; Murai, Keiichiro*; Arima, Hiroshi*; Katayama, Yoshinori

Precise structure analyses of advanced materials under pressure were performed using each advantage of X-ray absorption fine structure (XAFS) and diffraction methods. Measurements were performed in-situ under pressure and temperature using a large-volume multi-anvil pressure apparatus and synchrotron radiation. XAFS spectra are useful for phase study under high temperature and high pressure. The XAFS Debye-Waller factor provides anharmonic effective pair potential with a pressure-dependent and temperature-independent shape. The phonon energies and anharmonicity are affected largely by the change in local structure and bonding character.