Evidence for a recombination mechanism of cluster emission from ion bombarded metal surfaces

Classical dynamical calculations of the momentum dissipation of 600-20000 eV Ar+ in clean metal single crystals indicate that the experimentally observed cluster species form by a recombination mechanism in the near surface region. The dependence of cluster yields on primary ion energy has been computed and matches well the shape of the experimental curve for Ni3+/Ni2+. The results suggest that a simple power law based on the yield of monomers is not sufficient to predict accurate cluster yields. (Auth.)