AVS 46th International Symposium
    Applied Surface Science Division Tuesday Sessions
       Session AS-TuA

Paper AS-TuA5
Oxide-free Phosphate Films on Metals probed by Core and Valence Band X-Ray Photoelectron Spectroscopic Studies in an Anaerobic Cell

Tuesday, October 26, 1999, 3:20 pm, Room 6A

Session: Modeling in Applied Surface Science
Presenter: P.M.A. Sherwood, Kansas State University
Authors: J.A. Rotole, Kansas State University
P.M.A. Sherwood, Kansas State University
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This paper will show how clean metal surfaces can be reacted via aqueous electrochemical treatment in an anaerobic electrochemical cell to yield a phosphate film that can be directly attached to the metal surface without the presence of any intervening oxide. Such oxide-free films have the potential to serve as a corrosion inhibiting film, and may have other applications such as in the formation of biocompatible surfaces. Previously published work on aluminum and iron will be discussed but the focus of the paper will be new studies on copper. The work illustrates how it is essential to start with an oxide-free metal surface and to perform the treatment in an inert environment in an anaerobic electrochemical cell using aqueous phosphoric acid. It will also be seen that valence band photoemission, interpreted by band structure and other calculations, is a very effective tool for conclusively identifying the surface species present, and in particular distinguishing between oxide and phosphate surface films. This material was based upon work supported by the National Science Foundation under Grant No. CHE-9421068.