The diffusion of adatoms was studied on face-centered cubic polyhedral Al-cluster surfaces by using molecular dynamics simulations and effective medium theory. The diffusion at very low temperatures was shown to take place via hopping along {111} facets. The diffusion from one {111} facet to another {111} facet took place, at higher temperatures, via various mechanisms. Diffusion to, and along, {100} facets took place at high temperatures. Diffusion from {100} to {111} facets was possible only when close to the melting temperature of the cluster. The appearance of differing diffusion processes as a function of temperature was in good agreement with the calculated activation energies for various diffusion mechanisms. The latter included diffusion along different facets, and from one facet to another; including various hopping and exchange processes, plus a chain mechanism via a {100} facet between two {111} facets.

Diffusion on Aluminium-Cluster Surfaces and Cluster Growth S.Valkealahti, M.Manninen: Physical Review B, 1998, 57[24], 15533-40