Thermodynamic properties of perovskite MgSiO3 with cubic structure under extreme conditions

Abstract

The article applies the thermodynamic theory built by statistical moment method (SMM) to determine numerically the temperature and pressure dependences of the thermal expansion coefficient, the heat capacity constant pressure and the Gruneisen parameter of MgSiO₃ perovskite in the temperature range from 0 to 4000 K and in the pressure range from 0 to 135 GPa. Our SMM numerical results for MgSiO₃ perovskite are compared with that for CaSiO₃ perovskite, experimental data and results calculated by other methods. Our SMM numerical results are new and predictive of experimental results. This is the first application of SMM to study the thermodynamic characteristics of cubic MgSiO₃ perovskite under extreme conditions of the Earth’s lower mantle.

Graphical abstract