Fragmentation of sputtered cluster ions of transition metals : distributions of lifetimes and internal energies

Dissociation energies, lifetime distributions and internal energies have been determined experimentally for Fe-n(+) (4 less than or equal to n less than or equal to 10) clusters produced by sputtering under 8.5 keV Xe+ ion bombardment. The average lifetimes and the average internal energies were calculated from the experimental distributions. A comparison between the results of the present work on Ta-n(+) and Nb-n(+) clusters and those obtained earlier has been made. For all sputtered clusters compared, the linear dependence of the average internal energy (E) over bar(int) on the number of atoms, n, in the cluster has been identified. Good qualitative agreement has been found between experimental results and theoretical values determined from MD-simulations of cluster sputtering processes