Negative particle emission from Cs/Ru(0001) surface during exposure to NO and NO2
✍ Scribed by A. Böttcher; R. Grobecker; T. Greber; G. Ertl
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 480 KB
- Volume
- 208
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
Exposure of a monolayer of Cs adsorbed on a Ru (0001) surface to NO leads at first to dissociative chemisorption and in a later stage to molecular adsorption. During this latter stage emission ofexoelectrons signals the possibility for non-adiabatic processes, while with a clean surface efficient quenching of electronically excited states via resonance ionisation dominates. The behavior of NO closely resembles that of 02; however, in the latter case O-ions are also ejected. Interaction with NOz leads to qualitatively different results: Emission of exoelectrons is observed during the initial stage of dissociative chemisorption while at higher exposures NO? ions are ejected as well. The experimental findings are rationalized in terms of a model which takes the different electron affinities of the incident particles into account. The observation of a pronounced dependence of the yield of exoelectrons on the substrate temperature suggests the participation of a metastable intermediate phase.
' A. von Humboldt Fellow.