Oxygen-vacancy transport in acceptor-doped perovskites: effective medium approximation approach

A statistical theory, based on the effective medium approximation and master equation, is developed to describe oxygen-vacancy transport in AB1–xRxO3–δ perovskites taking into account inter-defect interactions. The role of acceptor-bound vacancy states and Fermi-type correlations is elucidated. The effects of inter-defect interaction on the dependence of oxygen-vacancy transport coefficients on dopant content and energetics of acceptor-bound states are established. Analytical findings are validated by Monte Carlo simulations, which also enable us to calculate the tracer diffusivity and determine the Haven ratio. The results can be useful for understanding transport phenomena in various acceptor-doped oxides promising for electrochemical applications.