Physical properties of MgO at deep planetary conditions

TL;DR

This study uses ab initio molecular dynamics to determine the physical properties and melting behavior of MgO under extreme conditions relevant to planetary interiors, aiding in accurate planetary modeling.

Contribution

It provides new EOS and melting curve data for MgO at high pressures, extending previous calculations to conditions relevant for giant planet cores.

Findings

High pressure melting temperature of MgO increases with pressure.

Results extend the pressure range of previous MgO studies.

Implications for the state of planetary cores containing MgO.

Abstract

Using ab initio molecular dynamics simulations, we calculate the physical properties of MgO at conditions extending from the ones encountered in the Earth mantle up to the ones anticipated in giant planet interiors such as Jupiter. We pay particular attention to the high pressure melting temperature throughout this large density range as this is a key ingredient for building accurate planetary interior models with a realistic description of the inner core. We compare our simulation results with previous ab initio calculations that have been so far limited to the pressure range corresponding to the Earth mantle and the stability of B1-B2 transition around 6 Mbar. We provide our results for both the EOS and high pressure melting curve in parametric forms for direct use in planetary models. Finally, we compare our predictions of the high pressure melting temperature with various interior profiles to deduce the state of differentiated layer within the core made of MgO in various types of planets and exoplanets.