The Effect of Oxygen Vacancies on the Atomic and Electronic Structure of Cubic ABO_3 Perovskite Bulk and the (001) Surface: Ab initio Calculations

摘要

We employed the hybrid DFT-LCAO and GGA-PW approaches as implemented in the CRYSTAL and VASP codes, respectively, for large supercell calculations of neutral O vacancies with trapped electrons (known as F centers) in the bulk and on the (001) surface of three cubic perovskite crystals (SrTiO_3, PbTiO_3, and PbZrO_3). The local lattice relaxation, charge redistribution, and positions of defect energy levels within the band gap are compared for three perovskites under study. We demonstrate how the difference in chemical composition of host materials leads to quite different defect properties.