Cluster on the fcc(111) surface: structure, stability and diffusion

The static and dynamical properties of a highly symmetric cluster on a fcc( lll) surface are studied using the molecular-dynamics method. We find that the cluster can only be stable on the surface up to a certain temperature m uch lower than the melting temperature of the corresponding isolated cluste r; the surface can strongly change the thermal properties of the cluster. T he fast diffusion of the cluster is attributed to the rolling of duster as a whole on the surface, and the dependence of diffusion constants on the st ructural mismatch is also studied. (C) 2000 Elsevier Science B.V. All right s reserved.