Sputtering from spherical Au clusters by energetic atom bombardment

Using molecular-dynamics simulation, we study the effect of 100 keV Au atom bombardment of spherical Au clusters (radius R=40 A), containing 15,784 atoms. Results range from projectile transmission with only few atoms sputtered to more or less complete cluster disintegration. During disintegration, besides major fragments of the original cluster, monatomics and a large number of clusters with sizes up to 100 atoms, and even beyond, are created. Angular and energy spectra of sputtered atoms show features of both collisional sputtering and evaporation: particle emission is isotropic with an additional contribution of preferential emission along [1 1 0] directions. Energy spectra show the high-energy E-2 fall-off typical of linear-cascade sputtering plus an additional low-energy thermal component