Phase Transformation in Mantle Minerals

Recent results of high pressure, high temperature experiments in the Inst. for Solid State Physics, Univ. of Tokyo

Abstract

Olivine-spinel transformation for Ni₂SiO₄, Fe₂SiO₄ and Co₂SiO₄ was examined using a tetrahedral anvil type high pressure apparatus. Tentative phase diagram of olivine-spinel transformation was presented for Ni₂SiO₄ and Fe₂SiO₄. Spinel form of Ni₂SiO₄, Fe₂SiO₄ and Co₂SiO₄ shows antiferromagnetic character at the lower temperature below 20°K. Abrupt change in electrical conductivity with olivine-spinel transformation was found for Ni₂SiO₄.