Enhanced ionic conductivity of Sm, Gd-doped ceria induced by modification of powder synthesis procedure

Nanostructured Ce0.85Gd0.05Sm0.10O2−δ powders have been obtained by a classical and a modified Pechini method. The textural parameters of the synthesized powders were evaluated using N2 adsorption–desorption. X-ray diffraction (XRD) showed that the powders were single phase with fluorite-type structure. The dilatometry measurements evidenced a strong influence of the synthesis procedure of Gd, Sm-co-doped ceria on its sintering behavior. A decrease in powder sintering temperature down to 1200 °C was obtained when Triton X-100 was added into the synthesis reaction mixture. The AC impedance spectroscopy of the sintered pellets was also performed in the 200–800 °C temperature range, in air. The sample prepared using the non-ionic surfactant exhibited higher ionic conductivities and lower activation energies than the sample synthesized by classical Pechini method over the entire investigated temperature range.