The electronic structures and bonding properties of the （110） polar terminations of cubic PbTiO3 were examined by the first-principles calculations at the generalized gradient approximation level. Two stoichiometric...The electronic structures and bonding properties of the （110） polar terminations of cubic PbTiO3 were examined by the first-principles calculations at the generalized gradient approximation level. Two stoichiometric （PbTiO and O2） and three nonstoichiometric（TiO, Pb, and O） terminations were considered in this study. With the aid of the calculated electron density differences, atomic charges, band structures, and densities of states, the charge redistributions and electronic properties were evaluated in detail. Furthermore, based on the calculated results of the cleavage energies, relaxation energies, and surface energies of the investigated terminations, the charge compensation by the modification of the surface stoichiometry and the fillings of surface states were thermodynamically evaluated.展开更多
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 elect...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.展开更多
基金Supported by the National Natural Science Foundation of China（Nos.21173072, 21301052） and the Program for Innovative Research Team in University, Ministry of Education of China（No.IRT-1237）.
文摘The electronic structures and bonding properties of the （110） polar terminations of cubic PbTiO3 were examined by the first-principles calculations at the generalized gradient approximation level. Two stoichiometric （PbTiO and O2） and three nonstoichiometric（TiO, Pb, and O） terminations were considered in this study. With the aid of the calculated electron density differences, atomic charges, band structures, and densities of states, the charge redistributions and electronic properties were evaluated in detail. Furthermore, based on the calculated results of the cleavage energies, relaxation energies, and surface energies of the investigated terminations, the charge compensation by the modification of the surface stoichiometry and the fillings of surface states were thermodynamically evaluated.
基金Supported by the National Natural Science Foundation of China（N os.21173072, 21301052）.
文摘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.
