The Preparation and Electrical Properties of La Doped Er0.2Ce0.8O1.9 Based Solid Electrolyte

The present trend is to investigate the co-doping approach in ceria either to improve further the electrical conductivity or sintering property. In this study, nano-structured Er and La co-doped ceria powders have been prepared by a novel solid state reaction method. In all the compositions, total dopant cation concentration has been kept at 0.20 atom fraction having general formulae Ce0.8Er0.2-xLaxO1.9 (0 <= x <= 0.06). The phase structure, sintering activity, relative density, microstructure, and electrical properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and AC impedance spectrum analyzer, respectively. All the samples calcined at 800 degrees C crystallized into cubic fluorite structure with the grain size between 20-25 nm, and La content has little impact on the grain size of the powders. SEM shows that the size of the crystal particles is of relatively uniform without pores with La addition 0.02 sintered at 1250 degrees C. When the content of La was 0.02, sintered at 1250 degrees C measured at 800 degrees C, the conductivity reached the maximum value of 3.5x10(-2) S cm(-1). Erbium and lanthanum co-doping in CeO2 is a promising electrolyte materials in low-temperature solid oxide fuel cells.