Chemical compatibility of RE0.6M0.4Mn0.8Co0.2O3-δ (RE=La, Pr, Nd, Sm and Gd; M=Sr and Ca) with yttria stabilized zirconia

The chemical compatibility of one new series, RE0.6M0.4Mn0.8Co0.2O3-δ (RE=La, Pr, Nd, Sm and Gd; M=Sr and Ca), with yttria stabilized zirconia (YSZ) has been examined. Powder mixtures of perovskites and YSZ were annealed at 1200° for 24h in air. RE0.6M0.4Mn0.8Co0.2O3-δ showed different compatibility towards YSZ for M=Sr and Ca, respectively. The formation of SrZrO3 was identified by X-ray diffraction analysis as a reaction product for RE0.6Sr0.4Mn0.8Co0.2O3-δ. In contrary, there is no reaction product for RE0.6Ca0.4Mn0.8Co0.2O3-δ. EDX analysis revealed that there is a larger difference between the solubility of Sr and Ca in YSZ. The bond-valence model was used to discuss the different compatibility of Sr and Ca series perovskites with YSZ. The present studies also showed that the formation of SrZrO3 was favored for larger disorder effect due to size difference between A-site RE3+ and Sr2+ in RE0.6Sr0.4Mn0.8Co0.2O3-δ.