Chemical damage resulting from 15 keV C60, Ar18 and Ar60 cluster bombardments of solid benzene

Abstract

Molecular dynamics simulations of 15 keV normal incidence cluster bombardment of solid benzene with Ar18, Ar60 and C60 were run for 50 ps using a mixed resolution model with the goal of elucidating the differences in chemical damage created in the crystal solid. The chemical damage in the solid for a single trajectory was found to be minor for all three clusters when compared with the total sputter yields; the largest number of damaged molecular benzene equivalents was only 28 ± 3 for Ar18 just two percent of the total sputter yield. All three clusters had relatively the same topography of chemical damage remaining in the crystalline solid. The damage was confined to the near surface region of the crystal with the overwhelming majority of damage confined to the crater created by the cluster impact. The chemical damage was also found to be approximately uniformly and randomly distributed around the crater. These findings demonstrate that for cluster bombardment of a small organic solid similar to molecular benzene, the total chemical damage remaining in the surface and the topography of the damage would be similar for Ar18, Ar60 and C60. Copyright © 2012 John Wiley & Sons, Ltd.