Theoretical Model for the High-Pressure Melting Process of MgO with the B1 Structure

TL;DR

This paper presents a theoretical model for understanding the high-pressure melting behavior of MgO, combining vibrational free energy calculations with a novel approach linking melting temperature to bulk modulus, providing insights into planetary processes.

Contribution

The paper introduces a simple yet effective theoretical model for MgO melting at high pressures, integrating vibrational free energies with a new relation to bulk modulus.

Findings

Successfully explains experimental melting data up to 370 GPa

Provides a quantitative link between melting temperature and bulk modulus

Offers insights into planetary mantle dynamics

Abstract

MgO is an abundant mineral in the rocky mantle of terrestrial planets, but its melting behaviors remain enigmatic. Here we introduce a simple theoretical model to investigate the B1-liquid transition of MgO up to 370 GPa. Vibrational free energies of B1-MgO are fully computed by the moment recurrence technique in quantum statistical physics. On that basis, we associate the melting temperature with the isothermal bulk modulus via the work-heat equivalence principle. This strategy allows us to quantitatively explain recent experimental data. Our numerical analyses would yield insights into planetary dynamics and evolution.