Thermodynamics of liquid noble-metal alloys through a pseudopotential approach

Abstract

On the basis of the Gibbs-Bogoliubov inequality and the Percus-Yevick hard-sphere model as a reference system, a thermodynamic perturbation method has been applied with use of the Borchi-DeGennaro pseudopotential. By applying a variation method the best hard-core diameters have been found which correspond to minimum free energy. With this procedure the thermodynamic properties such as entropy and heat of mixing have been computed. The computed excess entropy compares favorably in the case of these liquid alloys while the agreement with experiment is poor in the case of heats of mixing. The present results, even with the overlap contribution taken into consideration, still show the same trend as has been found by Umar et al. [J. Phys. F 4, 1691 (1974)]. This may be due to the sensitivity of the heats of mixing, as pointed out already by them, with the potential parameters, overlap correction, and the dielectric function.