Theory of Instability Phenomena and Its Application to Melting of Cubic Metals

Abstract

Melting temperature T_m of cubic metals is revaluated using the variation method, where anharmonicity of trial potential as well as crystal one is taken into account. The value of T_m is proportional to the dissociation energy D, and to the number of interactions between atoms which is properly estimated by using normal coordinates instead of each atomic displacement. We obtain the results which agree with the trend of the experiments that the straight line of T_m∝D for body centered cubic (BCC) is upper side than that for face centered cubic (FCC).