Thermo-elastic behavior of grossular garnet at high pressures and temperatures

Abstract

The thermo-elastic behavior of synthetic single crystals of grossular garnet (Ca3Al2Si3O12) has been studied in situ as a function of pressure and temperature separately. The same data collection protocol has been adopted to collect both the pressure-volume (P-V) and temperature-volume (T-V) data sets to make the measurements consistent with one another. The consistency between the two data sets allows simultaneous fitting to a single pressure-volume-temperature Equation of State (EoS), which was performed with a new fitting utility implemented in the latest version of the program EoSFit7c. The new utility performs fully weighted simultaneous fits of the P-V-T and P-K-T data using a thermal pressure EoS combined with any P-V EoS. Simultaneous refinement of our P-V-T data combined with that of KT as a function of T allowed us to produce a single P-V-T-KT equation of state with the following coefficients: