Fluid Flow and Effusive Desorption: Dominant Mechanisms of Energy Dissipation after Energetic Cluster Bombardment of Molecular Solids

作者：Brenes Daniel A; Garrison Barbara J; Winograd Nicholas^*; Postawa Zbigniew; Wucher Andreas; Blenkinsopp Paul

来源：Journal of Physical Chemistry Letters, 2011, 2(16): 2009-2014.

DOI：10.1021/jz200708j

The angular distribution of intact organic molecules desorbed by energetic C-60 primary ions was probed both experimentally and with molecular dynamics computer simulations. For benzo[a]pyrene, the angular distribution of intact molecules is observed to peak at off-normal angles. Molecular dynamics computer simulations on a similar system show the mechanism of desorption involves fast deposition of energy followed by fluid-flow and effusive-type emission of intact molecules. The off-normal peak in the angular distribution is shown to arise from emission of intact molecules from the rim of a crater formed during the cluster impact. This signature is unique for molecules because fragmentation processes remove molecules that would otherwise eject at directions near-normal to the surface.

• 出版日期2011-8-18