High-temperature behavior of metastable MgSiO3 perovskite: a Raman spectroscopic study

The thermal behavior of this compound has been investigated at ambient pressure. Thermally induced vitrification of the perovskite to an amorphous phase with Si in tetrahedral coordination begins near 400K and is complete by 750K. Irreversible frequency shifts of the perovskite Raman bands accompany the vitrification. Residual Raman shifts of samples thermally cycled into the vitrification region indicate a contraction of the perovskite lattice of up to 0.5% in volume