Origin of the diverse behavior of oxygen vacancies in ABO(3) perovskites: A symmetry based analysis

Article

关键词: TOTAL-ENERGY CALCULATIONS;    AUGMENTED-WAVE METHOD;    ELECTRON-GAS;    BASIS-SET;    SRTIO3;    SURFACE;   

DOI  :  10.1103/PhysRevB.85.201201

来源: SCIE

【 摘 要 】

Using band symmetry analysis and density functional theory calculations, we reveal the origin of why oxygen vacancy (V-O) energy levels are shallow in some ABO(3) perovskites, such as SrTiO3, but are deep in some others, such as LaAlO3. We show that this diverse behavior can be explained by the symmetry of the perovskite structure and the location (A or B site) of the metal atoms with low d orbital energies, such as Ti and La atoms. When the conduction band minimum (CBM) is an antibonding Gamma(12) state, which is usually associated with the metal atom with low d orbital energies at the A site (e. g., LaAlO3), then the VO energy levels are deep inside the gap. Otherwise, if the CBM is the nonbonding Gamma(25') state, which is usually associated with metal atoms with low d orbital energies at the B site (e. g., SrTiO3), then the V-O energy levels are shallow and often above the CBM. The V-O energy level is also deep for some uncommon ABO(3) perovskite materials that possess a low s orbital, or large-size cations, and an antibonding Gamma(1) state CBM, such as ZnTiO3. Our results, therefore, provide guidelines for designing ABO(3) perovskite materials with desired functional behaviors.

【 授权许可】

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