UPS Study on Adsorption Behavior of H₂O on Li₂O Surface

The adsorption behavior of H₂O on Li₂O surface was studied by ultra violet photo electron spectroscopy (UPS). Valence-band spectra of Li₂O single crystal which was exposed to different pressures of H₂O vapor were recorded. After exposure of H₂O, variation of the spectra was observed. The observed spectra were interpreted on the basis of ab-initio quantum chemical calculation of the electronic structure of Li₂O surface which was covered with –OH. The adsorbate-induced features were assigned as the orbital of surface –OH. The surface condition was varied by Ar ion sputtering and heat treatment under D₂ gas. The difference of adsorption behavior of H₂O in the surface condition was discussed.