Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1683966 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2009 | 4 Pages |
Abstract
Molecular dynamics computer simulations have been used to investigate the damage of a benzene crystal induced by 5Â keV C20, C60, C120 and C180 fullerene bombardment. The sputtering yield, the mass distributions, and the depth distributions of ejected organic molecules are analyzed as a function of the size of the projectile. The results indicate that all impinging clusters lead to the creation of almost hemispherical craters, and the process of crater formation only slightly depends on the size of the fullerene projectile. The total sputtering yield as well as the efficiency of molecular fragmentation are the largest for 5Â keV C20, and decrease with the size of the projectile. Most of the molecules damaged by the projectile impact are ejected into the vacuum during cluster irradiation. Similar behavior does not occur during atomic bombardment where a large portion of fragmented benzene molecules remain inside the crystal after projectile impact. 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.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Surfaces, Coatings and Films
Authors
B. Czerwinski, L. Rzeznik, R. Paruch, B.J. Garrison, Z. Postawa,