Chemisorption of a wide range of atoms and molecules can be studied by means of appropriate gas-handling facilities. A major area of research is the determination of the electronic and geometric structure of metal oxide surfaces. We study stoichiometric, nearly perfect single-crystal surfaces, surface defects, and chemisorption of a variety of gases on both types of surfaces. Measurements on perfect surfaces are necessary in order to compare with theoretical calculations of electronic structure, and the study of surface defects is a step towards understanding real surfaces and catalytically active sites. Some of our studies address the nature of the bulk electronic structure of transition-metal oxides.
Resonant photoemission is used to determine changes in surface interatomic bonding at defect sites.
Presently, we are interested in photochemical reactions that may take place on the surface of metal-oxide aerosols in the atmosphere. Experiments are under way to model atmospheric processes on well characterized surfaces of transition-metal oxides that are abundant in the troposphere. A number of other projects are also conducted in the Surface Science Laboratory, including Auger depth profiling of thin-film structures and the determination of surface and interface composition. V.E. Henrich, W.H. Casey, D.L. Clark, C. Eggleston, A. Felmy, D.W. Goodman, M. Gr tzel, G. Maciel, M.I. McCarthy, K. Nealson, D.A. Sverjensky, M.F. Toney, and J.M. Zachara, Chem. C. Smart and J. Nowotny, eds.