Synthesis, characterization, and electrical conduction of 10 mol% Dy2O3-doped CeO2 ceramics

Well-densified 10 mol% Dy2O3-doped CeO2 (20DDC) ceramics with average grain sizes of ∼0.12–1.5 μm were fabricated by pressureless sintering at 950–1550 °C using a reactive powder thermally decomposed from a carbonate precursor, which was synthesized via a carbonate coprecipitation method employing nitrates as the starting salts and ammonium carbonate as the precipitant. Electrical conductivity of the ceramics, measured by the dc three-point impedance method, shows a V-shape curve against the average grain size. The sample with the smallest grain size of 0.12 μm exhibits a high conductivity of ∼10−1.74 S/cm at the measurement temperature of 700 °C, which is about the same conduction level of the micro-grained 10 mol% Sm2O3- or Gd2O3-doped CeO2, two leading electrolyte materials.