Nitrate–citrate combustion synthesis and properties of Ce1−xCaxO2−x solid solutions

Nanocrystalline calcium-doped ceria powders for solid electrolyte ceramics were successfully prepared via a nitrate–citrate combustion route. The effect of ignition temperature on the characteristics of the powders were discussed. XRD indicated that a pure fluorite phase was formed at 160 °C. Using these powders, highly dense ceramics were prepared by sintering at much lower temperatures than 1700 °C, common for ceria solid electrolytes preparation by conventional ceramic techniques. The change of the crystal structure and electric conductivity with the content of doped Ca were also investigated.