Oxygen vacancy transport at Y₂O₃/CeO₂ interfaces: Insights from density functional theory

Oxygen-deficient fluorite oxides have shown fast oxygen transport, ideal for the solid electrolytes in solid oxide fuel cells. Crucial to their design are predictions of atomic-scale transport pathways in materials. For instance, while recent experimental studies of unique nanobrush geometries of Ceria-Ytria superlattices demonstrated that these materials exhibit excellent oxygen transport, little is known about the mechanisms that lead to this optimal behavior. Using first-principles methods, we have examined the oxygen vacancy transport at or near the interface in a Y₂O₃/CeO₂ superlattice model. Our results give insights in both the preference for oxygen vacancy formation as well as dynamics within the superlattice – having significant implications for the aforementioned nanobrushes.