Preparation and conductivity of Sc2O3–CeO2–ZrO2

The cubic 10Sc1CeSZ (10   mol% Sc 2 O 3 –1   mol% CeO 2 –89   mol% ZrO 2 ) was prepared by controlling the concentration of the urea varied from 0.4 to 0.6   mol/L in the hydrothermal process. XRD results depict that the 10Sc1CeSZ blocks have a stable cubic phase structure at room temperature after sintering at 1150–1450   °C. SEM characterization of the fracture surface of the 10Sc1CeSZ blocks shows that the grain size increases from 0.3 to 8   μm during heat treatment up to 1150–1450   °C, correspondingly, the relative densities increase from 98.3% to 99.7%. The impedance spectra measured at 300   °C reveal that the grain boundary resistance reduces with the increase of sintering temperature . Impedance analysis results show that the 10Sc1CeSZ block sintered at 1450   °C for 4   h has the highest total ionic conductivity of 0.137   S   cm −   1 at 800   °C.