The vacancy mechanism was simulated by using Monte Carlo methods in which impurity diffusion was assumed to occur via the migration of substitutional atoms by exchange with vacancies whose frequencies near to a solute atom differed from those of a free vacancy. When a defect left the lattice, the imposition of periodic boundary conditions brought it back into the lattice. The solute concentration profiles were given by using the Murch technique, which had been shown to be equivalent to a finite source. Fitting of these profiles permitted a comparison to be made between the present results and analytical solutions. The parameters which were extracted from a Gaussian function fit, that agreed well with numerical profiles, were in very good quantitative agreement with theoretical predictions.

Monte Carlo Study of the Vacancy Mechanism in Dilute FCC Binary Alloys. A.Hasnaoui: International Journal of Modern Physics – C, 2000, 11[7], 1417-23