The interaction of H2O with Fe-doped SrTiO3(100) surfaces

The interaction of H2O with 0.013 at.% Fe-doped SrTiO3(100) was investigated in situ with Metastable Induced Electron Spectroscopy (MIES), Ultraviolet Photoelectron Spectroscopy (UPS) and XPS at room temperature. Low Energy Electron Diffraction (LEED) was applied to gather information about the surface termination. To clear up the influence of surface defects, untreated and weakly sputtered SrTiO3 surfaces were investigated. The sputtering results in the formation of oxygen-related defects in the top surface layer. The interaction of untreated SrTiO3 surfaces with H2O is only weak. Small amounts of OH groups can be identified only with MIES due to its extreme surface sensitivity. Sputtered surfaces show a larger OH formation. Nondissociative H2O adsorption is not observed. We therefore conclude that the exposure of H2O to SrTiO3(100) results in the dissociation near surface defects only, resulting in the formation of surface hydroxyl groups. Copyright (C) 2010 John Wiley & Sons, Ltd.