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arXiv · 0910.0884

First-principles thermal equation of state and thermoelasticity of hcp Fe at high pressures

Xianwei Sha·R. E. Cohen
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Abstract

We investigate the equation of state and elastic properties of hcp iron at high pressures and high temperatures using first principles linear response linear-muffin-tin-orbital method in the generalized-gradient approximation. We calculate the Helmholtz free energy as a function of volume, temperature, and volume-conserving strains, including the electronic excitation contributions from band structures and lattice vibrational contributions from quasi-harmonic lattice dynamics. We perform detailed investigations on the behavior of elastic moduli and equation of state properties as functions of temperature and pressure, including the pressure-volume equation of state, bulk modulus, the thermal expansion coefficient, the Gruneisen ratio, and the shock Hugoniot. Detailed comparison has been made with available experimental measurements and theoretical predictions.

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Xianwei Sha, R. E. Cohen. 2009-10-05. First-principles thermal equation of state and thermoelasticity of hcp Fe at high pressures. https://doi.org/10.1103/physrevb.81.094105

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