The solid-state diffusion process in random binary alloys was simulated on a computer array of A and B atoms, coded in the relevant cubic symmetry. The process was a Monte Carlo sequence on which were superposed the appropriate conditions of concentration and defect-atom exchange frequencies. Correlation factors for atoms and vacancies were obtained for bcc and fcc random alloys. Their validity was verified for monatomic solids of the same symmetry, for which correlation factors were known to a high degree of accuracy from random walk analysis. The reproducibility of the simulation method varied between 4 and 1% contingent upon the degree of correlation. Semi-empirical polynomials of degree z-1 (z was the coordination number for the particular lattice symmetry) for -t versus concentration described the results obtained accurately (t defined by f = [1+t]/[1-t]). Comparison with the calculations of Manning showed discrepancies which were significant only when there was considerable correlation. There were substantial differences however between the present results and those of Kikuchi and Sato over the entire concentration and frequency ranges.

Diffusion Correlation in Random Alloys. H.J.De Bruin, G.E.Murch, H.Bakker, L.P.Van der Mey: Thin Solid Films, 1975, 25[1], 47-62