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Site Specificity in Stimulated Desorption from TiO2

  • Richard L. Kurtz
  • Roger Stockbauer
  • Theodore E. Madey
Part of the Springer Series in Surface Sciences book series (SSSUR, volume 4)

Abstract

We have applied synchrotron radiation methods, with other surface characterization techniques, to the study of ion production and desorption from single crystal TiO2. TiO2 is the model system for the Knotek-Feibelman mechanism [1] describing the production and desorption of O+ ions from its surfaces because it is a maximal-valent oxide. The Ti 3d-electron population on the stoichiometric, annealed surface is minimal [2] and the first occupied level, the 3p, is a relatively atomic-like core level. Reneutralization of a hole in this 3p level can occur via an inter-atomic Auger process leaving an O-ligand in a neutral or positively charged state, unstable in the local Madelung potential; this leads to the desorption of O+ ions. Non-maximal-valent TiO2 surfaces can be created, however, involving O-vacancy defects associated with appreciable Ti 3d electron population [2]. With 3d electrons present on surface Ti cations, an intra-atomic Auger decay is strongly favored and a reduced O+ ion yield is expected, based on the predictions of the Knotek-Feibelman mechanism [1]. As the surface Ti valence state is varied, we also produce surfaces having different O-ligand coordination of the surface Ti cations.

Keywords

Normal Emission Annealed Surface Ti02 Surface Cylindrical Mirror Analyzer Pulse Counting Mode 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1985

Authors and Affiliations

  • Richard L. Kurtz
    • 1
  • Roger Stockbauer
    • 1
  • Theodore E. Madey
    • 1
  1. 1.Surface Science DivisionNational Bureau of StandardsGaithersburgUSA

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