Synthesis, sintering and impedance spectroscopy of 8 mol% yttria-doped ceria solid electrolyte

CeO2–8 mol% Y2O3 solid solution was prepared by the coprecipitation technique. Cerium nitrate and yttrium oxide were used as precursors. The main purpose of this work was to evaluate some precipitation parameters, the densification behaviour of powder compacts, and the electrical resistivity of sintered ceramics. Results on thermal analyses show that the decomposition of the precipitated gel is almost complete at 400 °C. The specific surface area of calcined powders decreases for increasing precipitation temperature. For powders precipitated at room temperature, the BET surface area is also found to be dependent on the gel storage time before calcination. The densification of powder compacts increases sharply for sintering temperatures higher than 1400 °C. However, a few minutes at 1500 °C is sufficient for the compacts to attain a high densification. Impedance spectroscopy experiments reveal that the ionic resistivity is not dependent on most of the synthesis parameters, although the grain size play a key role in the intergranular component of the resistivity.