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Physical Society Colloquium
Thermal, Photo-induced and Electron-induced Reaction of Adsorbates on Si, by STM J. Polanyi
Department of Chemistry Heat, light and low-energy electrons have been used to induce reactions between sub-monolayers of halides and Si(111)77 or Si(100)21 substrates. The reaction dynamics were inferred from the alteration in the STM images of the individual molecules, due to the stimulus. Reagents were benzene, halobenzene, and multiply halogenated benzenes. The molecules were observed to desorb, diffuse to new sites, change their state of attachment, or undergo fragmentation accompanied by localised reaction with the substrate. These findings have been examined by ab initio calculations, also reported. The experiments were performed by Duncan Rogers, Harikumar Rajamma and Nan Li, and the theory by Guo-Ping Jiang and Fedor Y. Naumkin, all at the University of Toronto.
Friday, October 18th 2002, 15:30 |