Energetic Ion-Stimulated Desorption of Physisorbed Molecules
Energetic Ion-Stimulated Desorption of Physisorbed Molecules
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物理吸附分子的高能离子刺激解吸
DOI：
10.1021/jp0209906
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发表时间：
2002
影响因子：
3.3
通讯作者：
N. Winograd
中科院分区：
文献类型：
--
作者：
C. Meserole;E. Vandeweert;Z. Postawa;B. C. Haynie;N. Winograd
我们对8keV Ar+离子激发的分子脱附进行了实验研究。所研究的体系由吸附在Ag(111)表面的芳香族分子(苯和苯酚)组成。共振增强激光电离与飞行时间质谱仪相结合，提供了获得解吸分子的量子态分辨动能分布的能力。我们的结果表明，分子的脱附机制由分子覆盖度决定，并决定分子是否以内部激发态脱附。我们使用文献中报道的分子动力学模拟中观察到的特定机制来描述我们的实验观察。在低覆盖区，位错银衬底原子与吸附分子的弹道碰撞导致高能分子的发射。单个底物原子与被吸附分子的碰撞导致平移和内向发射。
We have conducted an experimental investigation into molecular desorption stimulated by 8 keV Ar+ ions. The investigated systems are comprised of aromatic molecules (benzene and phenol) adsorbed to an Ag(111) surface. Resonance-enhanced laser ionization coupled with time-of-flight mass spectrometry provide the ability to obtain quantum state resolved kinetic energy distributions of the desorbed molecules. Our results indicate that the desorption mechanisms for the molecules are dictated by the molecular coverage and determine if the molecules are desorbed in an internally excited state. We use specific mechanisms observed in molecular dynamics simulations reported in the literature to describe our experimental observations. In the low coverage regime, ballistic collisions between dislocated silver substrate atoms and the adsorbed molecules lead to the emission of energetic molecules. A collision between a single substrate atom and an adsorbed molecule leads to the emission of translationally and internall...