Ab initio study of the SrTiO3, BaTiO3 and PbTiO3 (0 0 1) surfaces

The results of first-principles calculations of the two possible terminations of (0 0 1) surfaces of SrTiO3 (STO), BaTiO3 (BTO) and PbTiO3 (PTO) perovskites are presented. Surface atomic structures and their electronic configurations have been calculated using ab initio density functional theory (DFT) combined with hybrid (B3PW) exchange-correlation technique. Our results are compared with previous quantum mechanical calculations and available experimental data. Surface relaxations and the electronic states near valence band gap are discussed in details for all three perovskites.