Influence of sintering temperature on microstructure and mixed electronic–ionic conduction properties of perovskite-type La0.6Sr0.4Co0.8Fe0.2O3 ceramics

Microstructural evolution and mixed electronic–ionic conduction properties of perovskite-type La0.6Sr0.4Co0.8Fe0.2O3 ceramics were investigated in the sintering temperature range 1100–1250 °C. The results confirm the crucial role of sintering temperature on microstructure and mixed conduction properties. The improvement of the mixed conduction properties with the increased sintering temperature from 1100 to 1200 °C is ascribed to the development of densification. Further increase of the sintering temperature above 1200 °C declined the mixed conduction properties due to the generation of excessive liquid. With respect to the mixed conduction properties, the preferred sintering temperature was ascertained to be 1200 °C for La0.6Sr0.4Co0.8Fe0.2O3 ceramics. The La0.6Sr0.4Co0.8Fe0.2O3 ceramic sintered at 1200 °C exhibited an electrical conductivity of 1.26×103 Ω−1 cm−1 and an oxygen ionic conductivity of 3.73×10−2 Ω−1cm−1 at 800 °C.