Stopping and Scattering of Slow Cluster Ions

Abstract

The interaction between slow (0.1–1.0 keV/atom) clusters with thin films has been studied by molecular dynamics simulation. Results are reported on the penetration of gold clusters through silicon [1] and on the interaction between carbon clusters with gold [2].Substantial differences in energy spectra and angular distributions have been found in a comparison of cluster bombardment with monoatomic bombardment at the same projectile speed. For the purpose of tracing the origin of these differences, simulations were performed with the various interatomic forces switched on and off in a systematic manner [3].Pronounced cluster effects were found in the specific energy loss per cluster atom, the energy spectrum of transmitted and reflected particles, and the energy spectrum of target recoils. In particular, pronounced tails were found of both projectile and target atoms with energies exceeding the kinematic limits familiar from linear collision cascades. The origin of these effects can be traced to clearing-the-way collisions [3], to collision cascades induced in the projectile cluster [4], and to multiply-hit target atoms [4].