Correlation factor in diffusion in the L12 structure for atomic migration via triple defects

Expressions for the diffusion coefficients and correlation factors for diffusion by means of divacancies in compounds A3B with the L12 structure are calculated. The divacancy is assumed not to dissociate and migrate via a triple-defect configuration. By applying a matrix method proposed by Howard [Phys Rev 1996;144:650], values for the correlation factors are calculated as a function of the ratio of the defect-atom exchange frequencies. The ratio of the diffusion coefficients of A and B atoms, DA/DB, will lie between 0.061 and 4.9.