Detailed insights into the structural properties and oxygen-pathways in orthorhombic Ba0.5Sr0.5Co0.8Fe0.2O3–δ by electronic-structure theory

A number of structural properties of orthorhombic Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) have been investigated by means of quantum-chemical calculations based on density-functional theory (DFT) and compared with experimental results. The role of the cation arrangements and the location of the oxygen vacancies within the orthorhombic structure have been evaluated and explained by means of bond-analytical techniques. Moreover, a detailed investigation of all oxygen pathways within orthorhombic BSCF has been performed, and the calculations show the existence of preferred oxygen pathways.

► A layered Ba2 +/Sr2 + arrangement in orthorhombic BSCF is favored. ► The vacancies are located close to cobalt which was confirmed by XANES experiments. ► Our calculations show that preferred oxygen pathways exist in orthorhombic Ba0.5Sr0.5Co0.8Fe0.2O2.75.