Formation and migration of oxygen vacancies in La1−xSrxCo1−yFeyO3−δ perovskites: insight from ab initio calculations and comparison with Ba1−xSrxCo1−yFeyO3−δ
Abstract
The formation and migration of oxygen vacancies in the series of (La,Sr)(Co,Fe)O3−δ perovskites, which can be used as mixed conducting SOFC cathode materials and oxygen permeation membranes, are explored in detail by means of first principles density functional calculations. Structure distortions, charge redistributions and transition state energies during the oxygen ion migration are obtained and analyzed. Both the overall chemical composition and vacancy formation energy are found to have only a small impact on the migration barrier; it is rather the local