The thermodynamically stable vacancy concentration was evaluated in Al-Mg solid solutions by means of atomistic simulations. The results were compared with data deduced from experiments based upon various models. It was shown that, in the presence of solute clustering, the stable vacancy concentration within the cluster could be orders of magnitude larger than the mean concentration in the absence of clusters. This assisted local solute diffusion.

Vacancy Concentration in Al–Mg Solid Solutions. R.C.Picu, Z.Xu: Scripta Materialia, 2007, 57[1], 45-8