Metallicity of the SrTiO3 surface induced by room temperature evaporation of alumina

It is shown that a metallic state can be induced on the surface of SrTiO3 crystals by the electron beam evaporation of oxygen deficient alumina or insulating granular aluminium. No special preparation nor heating of the SrTiO3 surface is needed. Final metallic or insulating states can be obtained depending on the oxygen pressure during the evaporation process. Photoconductivity and electrical field effect are also demonstrated.