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 degreesC. Using these powders, highly dense ceramics were prepared by sintering at much lower temperatures than 1700 degreesC, 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. (C) 2003 Elsevier B.V. All rights reserved.