Universal Equation of States are Derived from the Isothermal Relationships of Elastic Solids

TL;DR

This paper derives universal equations of state for elastic solids from established models, incorporating temperature effects, and validates them with experimental data on perovskite and periclase across wide pressure and temperature ranges.

Contribution

It introduces a universal form of P-V-T equations of state derived from Birch-Murnaghan and Vinet models, accounting for temperature dependence and validated with experimental data.

Findings

Parameters are valid across wide pressure and temperature ranges.

Root-mean-square misfits are below 1 GPa for both materials.

Universal equations accurately describe experimental data.

Abstract

Universal P-V-T equations of states are derived from the original isothermal expressions of Birch-Murnaghan and the Vinet EoSs by using absolute reference frame and incorporating the temperature dependence of the parameters. The equations are tested against the experiments of perovskite [MgSiO3] and periclase [MgO]. The determined parameters of the EoSs are valid throughout the entire pressure and temperature ranges, which cover 0-142 GPa and 293-3000 K and 0-109 GPa and 293-2199 K for periclase and perovskite respectively. The root-mean-square (RMS) misfits of the universal Birch-Murnaghan EoS are 0.73 and 0.33 GPa and the misfit of the Vinet EoS are 0.74 and 0.32 GPa for perovskite and periclase respectively.