ELECTRONIC-STRUCTURE OF ELECTRON-DOPED SRTIO3 - SRTIO3-DELTA AND SR1-XLAXTIO3

Electronic structures of electron-doped SrTiO3-delta and Sr1-xLaxTiO3 have been investigated within the ab initio band-structure approach us ing a supercell containing eight basic units. A small amount of electr on doping is found to drive SrTiO3 metallic, with the Fermi level movi ng into the conduction band in both the systems. Clustering of oxygen vacancies in the case of SrTiO3-delta gives rise to distinct non-rigid -band-like evolution of the electronic structure, trapping doped charg e carriers in midgap states; similar effects are not observed for Sr1- xLaxTiO3, explaining the difference in the Hall measurements of these two closely related compounds.