Equation of state for solids with mean-field anharmonicity

Abstract

Anharmonic contributions to the equation of state of solids are derived in closed form from a local mean-field potential for the atomic motion within the framework of the classical free-volume theory. The mean-field potential is calculated thereby from one cold isotherm and a series expansion of the partition function results in a good approximation for the anharmonic contribution up to the quartic terms. Quantum corrections are added to the classical terms to represent accurately experimental data for Cu, Ag, and Au.

Keywords:

• Equation of state (EOS)
• Anharmonicity
• Lattice dynamics
• Mean-field potential
• Thermo-physical properties of Cu, Ag and Au
• Heat capacity