Effect of transition metal oxides doping on Ce0.9Sm0.05Nd0.05O1.95 solid electrolyte materials

Abstract

The effect of transition metal oxides (TMOs) CoO1.5, FeO1.5 and MnO2 addition on Ce0.9Sm0.05Nd0.05O1.95 was studied. The crystal structures, microstructures, thermal expansion and electrical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), dilatometer and AC impedance spectroscopy, respectively. The results show that the TMOs addition remarkably promotes the densification of Ce0.9Sm0.05Nd0.05O1.95 and reduces the sintering temperature by ∼150 °C. The samples with TMOs addition sintered at 1450 °C exhibit higher conductivities than those sintered at 1500 °C. The maximum conductivity of 0.040 s.cm−1 at 700 °C was achieved with 1 mol% FeO1.5 doping when sintered at 1450 °C. In addition, the thermal expansion was linear for all the samples. The doping of TMOs does not appreciably change thermal expansion coefficient.