Oxygen content, cobalt oxide exsolution and defect structure of the double perovskite PrBaCo2O6−δ
Cobalt oxide exsolution as a result of reduction of A-site understoichiometric double perovskite Pr1−xBa1−xCo2O6−γ was found. The reasons for inconsistencies in the experimental data on oxygen content in PrBaCo2O6−δ reported by different authors were discussed. The step-like changes of the oxygen content of PrBaCo2O6−δ with pO2 in the temperature range 1023–1173 K were shown to correspond to reduction of exsolved Co3O4 to CoO. The defect structure analysis of PrBaCo2O6−δ was carried out using the conventional Kröger–Vink approach. The model proposed for the defect structure of PrBaCo2O6−δ was shown to coincide completely with available data on the oxygen content and crystal structure of this double perovskite.