Inelastic energy losses in cascades and atom ejection

Abstract

Recent molecular dynamics simulation studies demonstrated the important role that electronic stopping plays in the sputtering of metals when the loss rate is proportional to the velocity. Inelastic energy losses by the ions and energetic recoil atoms have relatively little effect, but losses by low energy atoms, late in the cascade, significantly reduce the ejected atom yield. The simulation results are consistent with recently obtained analytic results. Here ejected atom yield ratios, and energy and ejection time distributions are compared, with and without inelastic losses, for two simulation programs: TRIM.SP. a binary collision model, and QDYN, a multiple mteraction model. The results differ little within a given model, and the differences between models are well understood.