AVS 49th International Symposium
    Surface Science Tuesday Sessions
       Session SS3-TuA

Paper SS3-TuA10
Structure and Properties of SnOx Wetting Layers and Crystallites on Pt(111)

Tuesday, November 5, 2002, 5:00 pm, Room C-112C

Session: Metal/Oxide Surfaces
Presenter: J. Kim, University of Southern California
Authors: J. Kim, University of Southern California
M. Batzill, Tulane University
D. Beck, University of California-Los Angeles
B.E. Koel, University of Southern California
Correspondent: Click to Email
Tin-oxide films were grown on Pt(111) substrates by oxidation of Sn/Pt surface alloys using NO@sub 2@ exposures or by deposition of Sn in an NO@sub 2@ ambient gas. Based on the wide variety of structures of tin-oxide films that we have reported previously [Phys. Rev. B 64, 245402/1 (2001)], we now report detailed characterization of the vibrational and electronic properties of each structure using XPS, UPS, ELS, and HREELS. XPS confirmed the existence of three Sn states that have been labeled previously as metallic, "quasimetallic", and oxidic Sn. We conclude that the "quasimetallic" state results from oxidized Sn that is still alloyed within the Pt surface layer. UPS identified a SnO@sub 2@ stoichiometry for multilayer tin-oxide films. HREELS was used to identify characteristic vibrational modes for the different monolayer films. SnO@sub 2@ crystallites, although only a few monolayers high and tens of nanometers in width, remarkably exhibit bulk-like vibrational and electronic properties.