Kinetic theory of diffusion by vacancy pairs in mixed ionic compounds with the CsCl structure

Abstract

In this paper we adapt Manning's diffusion kinetics formalism for a random alloy to vacancy pair diffusion in ionic crystals of the CsCl structure. First, we analyse the binary ionic crystal and show that the formalism gives the component tracer correlation factors in closed form and with results in very good agreement with Monte Carlo simulation results. Next, we analyse quaternary mixed systems (two types of homovalent cation and two types of homovalent anion). Again the formalism gives all tracer correlation factors in closed form and the results are in very good agreement with those from Monte Carlo simulation.