title: Charge transfer in Cr adsorption and reaction at the rutile TiO2(110) surface.
abstract: The rutile TiO2(110) surface has been doped with sub-monolayer metallic Cr, which oxidises and donates charge to specific surface Ti ions. X-Ray and ultra violet photoemission spectroscopy and first principles density functional theory with Hubbard U are used to assign the oxidation states of Cr and surface Ti and we find that Cr2+ forms on bridging oxygen ions and a 5-fold coordinated surface Ti atom is reduced to Ti3+ and the Cr ions readily react with oxygen (to Cr3+), which leads to depletion of surface Ti3+ 3d electrons.
authors.affiliation: Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland. michael.nolan@tyndall.ie
authors.forename: Michael
authors.initials: M
authors.lastname: Nolan
authors.forename: James S
authors.initials: JS
authors.lastname: Mulley
authors.forename: Roger A
authors.initials: RA
authors.lastname: Bennett