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分离性附着的多种途径:CH3Br在Si100) - 2×1上
Ting Bin Lim1, Iain R McNab, John C Polanyi
1Department of Chemistry and Institute of Optical Sciences, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
Journal of the American Chemical Society
|June 24, 2011
概括
在表面的甲基化物解离性附着形式CH(3) 和Br. 观察到三种不同的几何形状,行间附着是最常见的,由理论计算支持.
科学领域:
- 表面科学是一门科学.
- 化学物理 化学物理
- 材料科学是一种材料科学.
背景情况:
- 甲基化物 (CH3Br) 是一种与大气化学和半导体加工相关的分子.
- 了解分子-表面相互作用对于开发新材料和新工艺至关重要.
研究的目的:
- 为了研究甲基化物在Si(100) - 2×1表面上的解离性附着 (DA).
- 为了确定CH3和Br碎片的首选附着几何和反应路径.
主要方法:
- 实验:超高真空扫描道显微镜 (UHV-STM) 在270 K.
- 理论: Ab initio计算用于解释实验观测和预测反应路径.
主要成果:
- 甲基化物通过热解离,在相邻的Si位点形成化学吸收的CH(3) 和Br.
- 观察到三种不同的附着几何形状:行间 (IR,88%),二极管间 (ID,11%) 和二极管内 (OD,1%).
- 最初的计算准确地预测了这些路径及其相对产量,将物理吸收几何与DA结果关联起来.
结论:
- 分离性附着的能量障碍以IR < ID < OD的顺序增加,控制观察到的产量.
- 理论和实验结果一致,提供了对甲基化物与Si100的相互作用的详细了解.
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