Two-dimensional diffusion of this type was studied by taking account of both temporal and spatial correlations between evaporation and condensation. It was shown that the effect of these correlations increased with time and with the diffusivity of the evaporated adatoms. The time dependence of cluster diffusion was non-linear, and the diffusion constant scaled with the reciprocal of the cluster radius; for very short times. At longer times, it scaled as the inverse square of the cluster radius. The effect of the perimeter energy was also non-negligible, and further changed the size dependence of cluster diffusivity.

J.M.Soler: Physical Review B, 1996, 53[16], R10540-3