Comparative Hybrid Hartree-Fock-DFT Calculations of ReO3, SrTiO3, BaTiO3, PbTiO3 and CaTiO3 (001) Surfaces

Abstract

We carried out comparative first principles calculations for the ReO2-terminated ReO3 as well as TiO2-terminated SrTiO3, BaTiO3, PbTiO3 and CaTiO3 (001) surfaces. As follows from our first principles calculations, systematic trend for the ReO2-terminated ReO3 as well as for TiO2-terminated SrTiO3, BaTiO3, PbTiO3 and CaTiO3 (001) surfaces is inward relaxation of all upper layer and outward relaxation of all second layer atoms. The only two exceptions from this systematic trend is outward relaxation of the first layer O atom on the TiO2-terminated PbTiO3 (001) surface as well as inward relaxation of the ReO2-terminated ReO3 (001) surface second layer O atom. Our calculated band gaps at the Γ-Γ point point for the ReO2-terminated ReO3 as well as TiO2-terminated SrTiO3, BaTiO3, PbTiO3 and CaTiO3 (001) surfaces in all cases are decreased regarding to the respective bulk values. Just opposite to the TiO2-terminated SrTiO3, BaTiO3, PbTiO3 and CaTiO3 (001) surfaces, where the Ti-O chemical bond population are larger than in the bulk, near the ReO2-terminated ReO3 (001) surface, the Re-O chemical bond population is reduced in comparison to the bulk value.