Sputtering of neutral clusters from silver–gold alloys

Abstract

Polycrystalline Ag, Ag 20Au 80, Ag 40Au 60, Ag 80Au 20 and Au samples were bombarded with 15 keV Ar + at 60° incidence and the resulting secondary neutral yield distribution was studied by non-resonant laser postionisation mass spectrometry. Neutral clusters containing up to 21 atoms were observed for the targets. The yield of neutral clusters, Ag m Au n− m , containing n atoms, Y n , was found to follow a power in n, i.e. Y n ∝ n − δ , where the exponent δ varied from 3.2 to 4.0. For a fixed n, the cluster yields showed a variation with number of gold atoms similar to that expected for a binomial distribution. In addition, the cluster compositions from the sputtered alloys were indicative of sputtering from a gold rich surface.