Electronic Properties of BaTiO3 （110） Polar Terminations

The band structures, electron, density differences, and surface energies of five different BaTiO3 （110） ter- minations were investigated by first-principles calculations. According to the calculated results of electron density differences, the bonding characteristics of these considered terminations were discussed. The computational results indicate that the BaTiO-terminated surface is metallic, while the 02-, O-, Ba- and TiO-terminated surfaces are all in- sulative. Furthermore, the computed surface energies suggest that for the considered terminations, the polarity com- pensation achieved through surface reconstruction or surface defect is more effective than by change in surface elec- tronic structure. The defected or reconstructed terminations predominate over cleavage and construction of BaTiO3 crystal along （110） direction.