ADSORPTION AND THERMAL-STABILITY OF MN ON TIO2(110) - 2P X-RAY-ABSORPTION SPECTROSCOPY AND SOFT-X-RAY PHOTOEMISSION

X-ray absorption and photoelectron spectroscopies are used to study th e adsorption and reaction of Mn films deposited on TiO2(110) at 25 deg rees C and after annealing to similar to 650 degrees C. Fractional mon olayer coverages of Mn at 25 degrees C produce a reactive, disordered interface consisting of reduced Ti cations and oxidized Mn overlayer a toms. Metallic Mn is found only for thicker layers at 25 degrees C. An nealing Mn films to -650 degrees C leads to several changes that are l argely independent of initial overlayer coverage: Metallic Mn thermall y desorbs leaving only Mn2+ ions; interfacial Ti cations are largely r e-oxidized to the Ti4+ state; and the local order is increased at the interface. The formation of a crystalline ternary surface oxide, MnTiO x, is proposed to account for these chemical and structural changes.