ELECTRONIC-STRUCTURE OF TIN OXIDES - HIGH-RESOLUTION STUDY OF XPS AND AUGER-SPECTRA

High-resolution core and valence band photoemission as well as photoinduced Auger spectra of metallic Sn, polycrystalline SnO and SnO2 ((110) natural single-crystal cassiterite and polycrystalline) samples were measured in order to give information on local electronic and geometric structures around the core-ionized atoms and far providing data for facilitating quantitative analysis of systems containing these species, The SnO surfaces were obtained without the use of ion sputtering by using a special preparation procedure based on in vacuo surface scraping, The respective experimental valence land spectra could be utilized in quantitative analysis of layered tin oxide structures. Valence band spectral shapes are compared to spectra calculated by using a cluster-type (DV-X alpha) MO model. From the Sn Auger parameter measurements, using a simple electrostatic model, the similarity of the initial-state effects for the two oxides was deduced, while the oxygen Auger parameter values indicated large polarizability and the respective final-state hole-hole repulsion energies were determined.