Electrical and structural properties of Ce0.8(Sm0.5−xY0.5Alx)0.2O2−δ ceramics as an electrolyte for SOFC

The effects of various contents of alumina co-doping on a ceria-based electrolyte were investigated. All samples were sintered at 1500 °C for 10 h. The X-ray diffraction (XRD) patterns showed a fluorite cubic structure. To investigate the surfaces of the Ce0.8(Sm0.5−xY0.5Alx)0.2O2−δ (CSYA) ceramics by scanning electron microscopy (SEM), the electrical properties of the CSYA ceramics were measured by AC impedance. The optimal values of ionic conductivity and activation energy were reached at x = 0.4 measured at 600 °C. This result indicated that the alumina co-doping improved the electrical and microstructural properties of the ceria-based electrolyte.