Effect of Y and Dy co-doping on electrical conductivity of ceria ceramics

The effect of co-joint additions of Y and Dy on the electrical conductivity of ceria ceramics was studied by impedance spectroscopy. Powder materials were synthesized by aqueous coprecipitation to obtain Ce1−x(Y0.5Dy0.5)xO2−δ with 0 ≤ x ≤ 0.15. Sintering of powder compacts was carried out at 1450 °C for 4 h. The main results show that high densification (∼95% of theoretical value) was attained for all compositions. Raman spectroscopy results evidenced the solid solution formation among cerium, yttrium and dysprosium. The electrical conductivity of sintered specimens varies with the total dopant content. A maximum conductivity value was obtained for a lower dopant content considering the behaviour of singly doped ceramics. Moreover, sintered specimens with the same total dopant content exhibit similar electrical conductivity values suggesting that the concentration of oxygen vacancies play a major role in the conduction process of co-doped ceramics.