Regensburg 2004 – wissenschaftliches Programm
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O: Oberflächenphysik
O 10: Teilchen und Cluster I
O 10.7: Vortrag
Montag, 8. März 2004, 17:15–17:30, H43
Molecular dynamics simulations of self-sputtering of silver under bombardment with Ag4 projectiles — •Andreas Duvenbeck and Andreas Wucher — Institut für experimentelle Physik, Universität Duisburg-Essen, 45117 Essen
The self-sputtering of a Ag(111) surface with Ag4 projectiles has been investigated by classical molecular dynamics (MD) simulations using the many body MD/MC-Corrected Effective Medium potential developed by De Pristo et al. The calculation of a set of several thousands of trajectories in the energy range from 1−8keV has been carried out for a microscopic study of nonlinear yield enhancements that have been observed in recent polyatomic sputtering experiments. We will show that the application of Ag4 instead of monoatomic silver projectiles at the same impact velocity, i.e the same energy per projectile atom, leads to an exponential yield enhancement as a function of the impact velocity. A detailed analysis of the kinetic energy transfer processes during the spatial and time evolution of the collision cascade shows that this phenomenon cannot only be explained by a higher energy density at the surface due to the strongly localized overlap of collison cascades.