A Monte Carlo study was made of the linear enhancement factor, for solvent tracer diffusivity in dilute face-centered cubic alloys, using the well-known 5-frequency model; with isolated solute atoms. It was shown that the Howard-Manning and Ishioka-Koiwa analytical treatments exhibited major shortcomings with respect to their handling of correlation effects for certain combinations of the atom-vacancy exchange frequencies. It was suggested that many of the published values of exchange frequency ratio, deduced from experiments by using these treatments, were probably wrong to some extent.

Computer Simulation of Solute-Enhanced Diffusion Kinetics in Dilute FCC Alloys. I.V.Belova, G.E.Murch: Philosophical Magazine, 2003, 83[3], 377-92