First-principles thermoelasticity of bcc iron under pressure

TL;DR

This study uses first-principles calculations to analyze the thermoelastic properties of ferromagnetic bcc iron under various temperatures and pressures, incorporating electronic and phonon contributions for accurate modeling.

Contribution

It provides a comprehensive first-principles approach to predict elastic properties of bcc iron considering both electronic and phonon effects under different conditions.

Findings

Elastic moduli vary with temperature and pressure.

Good agreement with experimental data.

Electronic and phonon contributions significantly influence properties.

Abstract

We investigate the elastic and isotropic aggregate properties of ferromagnetic bcc iron as a function of temperature and pressure by computing the Helmholtz free energies for the volume-conserving strained structures using the first-principles linear response linear-muffin-tin-orbital method and the generalized-gradient approximation. We include the electronic excitation contributions to the free energy from the band structures, and phonon contributions from quasi-harmonic lattice dynamics. We make detailed comparisons between our calculated elastic moduli and their temperature and pressure dependences with available experimental and theoretical data.