Effect of impact angle and projectile size on sputtering efficiency of solid benzene investigated by molecular dynamics simulations

Abstract

Molecular dynamics computer simulations have been used to investigate the effect of the cluster size on the sputtering yield dependence on the impact angle. Ar366 and Ar2953 cluster projectiles with 14.75keV of incident energy are directed at the surface of a solid benzene crystal described by a coarse-grained representation at angles between 0° and 70°. It is observed that the shape of the angular dependence of sputtering efficiency is strongly affected by the cluster size. For the Ar366 cluster, the sputtering yield only slightly increases with the impact angle, has a broad maximum around 40°, and decreases at larger angles. For the Ar2953 cluster, the yield strongly increases with the impact angle, has a maximum around 45° followed by a steep decrease at larger angles. For both investigated cluster projectiles the primary energy is deposited so close to the surface so that the sputtering efficiency only weekly benefits from the shift of the deposited energy profile toward the surface which occurs at larger impact angles. In this study, molecular dynamics computer simulations are used to probe the effect of the impact angle on the efficiency of ejection molecules emitted from solid benzene by 14.75keV Ar366 and Ar2953 clusters.