Application of statistical moment method to thermodynamic properties of metals at high pressures

The moment method in statistical dynamics is used to study the thermodynami c properties of metals taking into account the anharmonicity effects of the lattice vibrations and hydrostatic pressures. The explicit expressions of the lattice constant, thermal expansion coefficient, and the specific heats C-v and C-p of cubic (fcc) metals are derived within the fourth order mome nt approximation. The thermodynamic quantities of Al, Au, Ag, Cu; and Pt me tals are calculated as a function of the pressure, and they are in good agr eement with the corresponding experimental results. The effective pair pote ntials work well for the calculations of transition and noble metals, compa red to those of the sp-valence metals. For obtaining better agreement of th e thermodynamic quantities of metals like Al, it is required at least to us e the more sophisticated electronic many body potentials. In general, it ha s been shown that the anharmonicity effects of lattice vibration play a dom inant role in determining the thermodynamic properties of metals under high pressures and at the finite (high) temperatures.