Thermodynamic quantities of metals investigated by an analytic statistical moment method

Abstract

The thermodynamic properties of metals are studied by including explicitly the anharmonic effects of the lattice vibrations going beyond the quasiharmonic approximations. The free energy, thermal lattice expansion coefficients, mean-square atomic displacements, and specific heats at the constant volume and those at the constant pressure, Cv and Cp, are derived in closed analytic forms in terms of the power moments of the atomic displacements. The analytical formulas give highly accurate values of the thermodynamic quantities, which are comparable to those of the molecular dynamics or Monte Carlo simulations for a wide temperature range. The present formalism is well suited to calculate the thermodynamic quantities of metals and alloys by including the many body electronic effects and by combining it with the first-principles approaches.