Welcome to Yagi Labo.

Main subject of this group is the study of materials under very high pressures and high temperatures from the view poit of the Earth science and material sciences. High pressure in situ X-ray diffraction study provides us many important informations on the behavior of materials under pressure. Pressure induced phase transformations, structural analysis of the high pessure phases, equations of state, are studied using this technique. Large efforts are concentrated recently to the development of a new high pressure and high temperature apparatus using sintered diamond as anvil materials. By combining this apparatus wuth a very intense X-ray soutce such as synchrotron radiation, it became possible to extend the pressure and temperature range of the in situ X-ray observations considerably. Among the recent interesting topics are the findings of the graphite-hexagonal diamond transition at about 18 GPa and room temperature, in-site X-ray observation of the silicate perovskite under lower mantle condition, and the findings of unquenchable high pressure polymorphs of iron hydrides and Ca berring silivates.