Dynamical Theory of Diffusion in Crystals

Abstract

The theory of self-diffusion in a crystal via the vacancy mechanism is investigated from a detailed dynamical model. It is shown that the parameters which determine the diffusion coefficient can be defined in terms of the normal coordinates of the crystal. The effects of lattice imperfections are considered explicitly in the formulation in the normal mode analysis, but no detailed analysis is given. The effects of the correlation in motion of atoms is considered and some comments on the physical nature of the contributions to the enthalpy and entropy of activation are presented.