Correlation of Properties of Materials to Debye and Melting Temperatures

Many solid state properties are correlated to simple parameters like the atomic mass, the interatomic distance and some measure of the strength of the interatomic interaction, e.g. the melting temperatureTmor some Debye temperature θD. Such empirical relations are investigated for elastic properties, melting temperature, thermal expansion, vacancy formation energy, grain boundary and surface energy, cohesive energy, heat of fusion, activation energies for bulk, grain boundary, surface and dislocation pipe diffusion, viscosity, activation energy for creep, recrystallization temperature and other properties. When experimental data are available, both elements and diatomic compounds (alkali halides, oxides, carbides, III-V semiconductors) are considered. The correlations toTm, θD(T= 0) and a high temperature effective θDare compared. It is found that for all practical purposesTmgives the best correlation. For diatomic compounds, the average mass is not uniquely defined and various averages are discussed. The purpose of the paper is not only to present empirical relations but also to give a short account of the possibilities to calculate the considered parameters using solid state theory in its most advanced present state.