Model studies of particle/solid interactions

The interaction of keV particles with surfaces has traditionally been expressed in terms of successive single binary elastic collisions. In this study, molecular dynamics calculations of 100 eV to 6 keV incident particles scattering from single crystal surfaces are performed using three particle interaction models. We find that for some incident conditions, a simultaneous interaction model is needed to produce accurate trajectory simulations. This extended model takes into account the simultaneous interactions among the primary particle and all the other atoms in the system but not the ones among the substrate atoms. A fair agreement between the calculated results of this extended interaction model and that of the full dynamics model is observed for nearly the entire energy regime studied. The range of primary energies where the binary collision model is adequate in describing forward scattering processes is discussed.