A Universal Analytical Approach to the Defect Chemistry of A+2B+4O3 Perovskites

Abstract: An analytic link between the oxygen partial pressure and the concentrations of the native point defects for given temperatures and A/B ratios is presented. A general equation is developed from important mass action relations, electroneutrality and consideration of Gibbs’ phase rule. This general equation is solved without the need to divide the existence regime to sub-regimes. Furthermore, the concentrations of metal vacancies obtained during sintering are calculated. Meta-stable states, resulting from non equilibrated metal vacancies concentrations, are considered to exist at low temperatures and/or in large grain sized ceramics. The consequences of these cases are discussed.

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