Effect of the sintering temperature on the properties of Ce0.85La0.10Ca0.05O2−δ electrolyte material

Rare earth and alkaline earth co-doped Ce0.85La0.10Ca0.05O2−δ electrolyte material with the powder obtained by solid-state reaction method was sintered at 1300, 1400, 1500 and 1600 °C respectively. The results showed that the ionic conductivity of the sample sintered at 1400 °C was slightly lower compared to that sintered at 1500 °C in the temperature range of 300–550 °C, while the sample sintered at 1400 °C showed the highest ionic conductivity in all the samples above 550 °C. The ionic conductivity of ∼0.021 S/cm at 600 °C and the relative density of 98.2% were observed for the sample sintered at 1400 °C. In addition, the highest flexural strength with 145 MPa was also obtained for the sample sintered at 1400 °C. It suggested that the sintering temperature for Ce0.85La0.10Ca0.05O2−δ electrolyte may be reduced to as low as 1400 °C with desired properties.