Molecular dynamics computer simulations of 5 keV C60 bombardment of benzene crystal

Coarse-grained molecular dynamics computer simulations have been used to investigate the damage of a benzene crystal induced by 5 keV C-60 projectile bombardment. The sputtering yield, mass distributions and the depth distributions of ejected organic molecules are analyzed. The temporal evolution of the system reveals that impinging C60 cluster leads to creation of almost hemispherical crater. Most of the molecules damaged by the projectile impact are ejected into the vacuum during cluster irradiation. This "cleaning up" effect may explain why secondary ion mass spectrometry (SIMS) analysis of some organic samples with cluster projectiles can produce significantly less accumulated damage compared to analysis performed with atomic ion beams. (C) 2009 Elsevier Ltd. All rights reserved.