Expressions for the diffusion coefficients and correlation factors for diffusion by means of divacancies in compounds A3B with the L12 structure were calculated. The divacancy was assumed not to dissociate and migrate via a triple-defect configuration. By applying a matrix method proposed by Howard (1996), values for the correlation factors were 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, were expected to lie between 0.061 and 4.9.

Correlation Factor in Diffusion in the L12 Structure for Atomic Migration via Triple Defects. Nobuaki, K., Masahiro K.: Intermetallics, 2002, 10[7], 735-41