Electrical Properties of Co-Doped Ceria Electrolyte $Ce_{0.8-x}Gd_{0.2}Sr_{x}O_{2-δ}$ (0.0 ≤ x ≤ 0.1)

Effects of strontium doping on electrical properties of gadolinium-doped ceria were investigated. The $Ce_{0.8-x}Gd_{0.2}Sr_{x}O_{2-δ}$ (0.0 ≤ x ≤ 0.1) compositions were prepared by sol-gel method and sintered at 1300°C for 8 h, the bulk densities were over 93% of theoretical density. These results were consistent with scanning electron microscope. The crystallite size of these materials was determined using the X-ray powder diffractometer and the sizes range from 19.4 nm to 24.4 nm. From the experimental results, it was observed that the composition $Ce_{0.8-x}Gd_{0.2}Sr_{x}O_{2-δ}$ (x=0.02) exhibits higher conductivity (23.6× $10^{-3}$ S $cm^{-1}$) and minimum activation energy (0.83 eV) at 700°C. This composition is thus a potential candidate for use as electrolyte applications in intermediate temperature solid oxide fuel cells.