A study was made of the migration of spherical Sb clusters which had been deposited onto graphite surfaces. Good agreement with computer simulations was found, and this fact was used to deduce the diffusivity of clusters, which contained about 2300 Sb atoms, on the substrate. The results (table 31) could be described by:

D(cm2/s) = 16000 exp[-0.7(eV)/kT]

The large value of the pre-exponential factor suggested that the diffusion could not be explained in terms of a simple activated process, but instead involved the collective motion of the atoms of the cluster.

L.Bardotti, P.Jensen, A.Hoareau, M.Treilleux, B.Cabaud: Physical Review Letters, 1995, 74[23], 4694-7