Molecular dynamics simulations with electronic stopping can reproduce experimental sputtering yields of metals impacted by large cluster ions

摘要

Highlights•We incorporate electronic stopping (ES) into molecular dynamics (MD) simulations to simulate continuous bombardments of keV large cluster projectiles (C60and Ar100) on metals (Ag and Au).•We obtain sputtering yields very close to experimental results, which has never been achieved in the research of spike sputtering on metals bombarded by large cluster projectiles.•Our results provide a possible explanation for the differences between the simulated and the experimental sputtering yields found in the previous studies of large cluster bombardments on metals.•Our work is the first time that ES is considered in MD simulations of sputtering induced by large clusters, and highlights the importance of addressing ES in MD simulations.AbstractAn unsolved problem in research of sputtering from metals induced by energetic large cluster ions is that molecular dynamics (MD) simulations often produce sputtering yields much higher than experimental results. Different from the previous simulations considering only elastic atomic interactions (nuclear stopping), here we incorporate inelastic electrons–atoms interactions (electronic stopping, ES) into MD simulations using a friction model. In this way we have simulated continuous 45° impacts of 10–20keV C60on a Ag(111) surface, and found that the calculated sputtering yields can be very close to the experimental results when the model parameter is appropriately assigned. Conversely, when we ignore the effect of ES, the yields are much higher, just like the previous studies. We further expand our research to the sputtering of Au induced by continuous keV C60or Ar100bombardments, and obtain quite similar results. Our study indicates that the gap between the experimental and the simulated sputtering yields is probably induced by the ignorance of ES in the simulations, and that a careful treatment of this issue is important for simulations of cluster-ion-induced sputtering, especially for those aiming to compare with experiments.