AVS 49th International Symposium
    Surface Science Monday Sessions
       Session SS2-MoM

Paper SS2-MoM9
Identification of Defect Sites on Oxide Surfaces

Monday, November 4, 2002, 11:00 am, Room C-112C

Session: Oxide Structure and Surface Chemistry
Presenter: Y.D. Kim, Texas A&M University
Authors: Y.D. Kim, Texas A&M University
J. Stultz, Texas A&M University
T. Wei, Texas A&M University
A.K. Santra, Texas A&M University
D.W. Goodman, Texas A&M University
Correspondent: Click to Email
Defect sites on oxide surfaces play an important role in various catalytic reactions, as well as in adhesion and in nucleation of metal clusters. Thus, identification and quantification of defect sites on oxide surfaces are important steps in the understanding of many catalytic reactions. Recently we have used several techniques to identify various defect sites on oxide surfaces including metastable impact electron spectroscopy (MIES), water and CO-temperature programmed desorption (TPD), MIES of adsorbed Xe (MAX), and electron energy loss spectroscopy (EELS). MIES data for MgO(100) and SiO2 thin films are very sensitive to extended defect sites as well as point defect. Point defects result in the appearance of band gap states, whereas extended defects cause broadening of the O(2P) band. MAX data change significantly with increasing defect densities for various oxide surfaces. The adsorption of D2O and CO also has been used to identify various defect sites since their TPD spectra change significantly in the presence of defect sites. Recent EELS data acquired for low and highly defective oxide surfaces will also be discussed.