Equation of state and elastic properties of face-centered-cubic FeMg alloy at ultrahigh pressures from first-principles

TL;DR

This study uses first-principles calculations to investigate how magnesium influences the equation of state and elastic properties of face-centered cubic iron at ultrahigh pressures, revealing significant softening and increased anisotropy.

Contribution

It provides new insights into the effects of Mg addition on Fe's properties under extreme conditions using first-principles methods.

Findings

Mg causes significant softening of elastic constants in Fe.

Elastic anisotropy increases with Mg addition and pressure.

Mg influences the equation of state of Fe at ultrahigh pressures.

Abstract

We have calculated the equation of state and elastic properties of face-centered cubic Fe and Fe-rich FeMg alloy at ultrahigh pressures from first principles using the Exact Muffin-Tin Orbitals method. The results show that adding Mg into Fe influences strongly the equation of state, and cause a large degree of softening of the elastic constants, even at concentrations as small as 1-2 at. %. Moreover, the elastic anisotropy increases, and the effect is higher at higher pressures.