Empirical rules

Abstract

The extent to which empirical relations have been tested for the estimation of diffusion data in ceramic diffusion systems is not known to the author. However, some of the known empirical rules, such as the melting point and the activation energy have been found to apply to ceramics also. Some empirical relations have been tested and corroborated experimentally. It would be desirable to check the applicability of some of the rules to ceramics as well. The empirical rules considered in this chapter are: (1) Diffusion distance, (2) D and melting point, (3) The activation energy relation, (4) The enthalpy of heat of evaporation and the activation energy, (5) D 0 Evaluation and (6) Effect of impurity.