[S-MP26] Physics and Chemistry of Minerals

[SMP26-P03] Phase transition of M3+OOH-type oxyhydroxides under high pressure

*Akio Suzuki¹ (1.Department of Earth Science, Graduate School of Science, Tohoku University)

Keywords:hydrous phase, mantle, high pressure, water, AlOOH, InOOH

Water is transported by the subducting slab into the Earth’s interior by hydrous phases. Suzuki et al. (2000) synthesized a high-pressure phase of AlOOH and named it the delta-phase. The crystal structure of the delta-phase is isostructural with InOOH. The study on the stability and transition of the M3+OOH-type oxyhydroxides is very important to investigate the transportation of hydrogen in the Earth’s interior. In this study, the phase transition of InOOH was investigated under high pressures and high temperatures. In situ X-ray diffraction study was carried out using multianvil techniques and synchrotron light source at the High Energy Accelerator Research Organization (KEK) in Japan. Based on the time-resolved diffraction measurements, we observed the phase transition from the distorted rutile structure to the pyrite structure of InOOH around 10 GPa.