Water as a source for oxygen incorporation into acceptor doped SrTiO3 single crystals

The possibility of the incorporation of oxygen and deuteron stemming from the dissociation of water into iron doped strontium titanate single crystals with two different iron concentrations (0.13 and 0.013 at.% Fe) has been investigated. Double labeled water (2H218O) was used for Isotope Exchange Depth Profiling. It acts as an incorporation source of 18O into Fe-doped SrTiO3(100) single crystals. Total dissociation of the water takes place in the vicinity of the SrTiO3 surface and both oxygen and deuteron incorporate into the SrTiO3. The results of the diffusion profile evaluation confirm that oxygen and deuteron migrate independently in the bulk. Oxygen incorporates into the material at high incorporation rates, practically comparable with the ones resulting from an O2 atmosphere. The interaction of H2O with SrTiO3(100) surfaces was further studied with Metastable Induced Electron Spectroscopy and Ultraviolet Photoelectron Spectroscopy. Neither partial dissociation of water molecules nor any significant formation of surface OD groups was observed.