First-principles molecular dynamics simulations were used to investigate the predominant migration mechanism of the Ga vacancy, as well as its free energy of formation and the rate constant for Ga self-diffusion. The results suggested that the vacancy migrated via second-nearest neighbor hopping. The calculated diffusion constant was in good agreement with the experimental value which was deduced by using 69GaAs/71GaAs heterostructures. However, the predictions differed considerably from the results which had been obtained by performing interdiffusion experiments on GaAlAs/GaAs heterostructures.

M.Bockstedte, M.Scheffler: Zeitschrift für Physikalische Chemie, 1997, 200[1-2], 195-207