The effects of low temperature processes and the dopants of bismuth, manganese and iron co-doping in Ce1-x,Mx)O2 materials have been investigated. The CeO2-based powders were synthesized by EDTA-citric acid method and their sintering behavior was analyzed by dilatometry (DIL) and density measurement. X-ray diffraction (XRD) and various electron microscopies were used to identify crystalline phases and microstructure. The results show that solubility limit of Mn and Fe in ceria is less than 1 at% while that of Bi is at 8-9 at%. Two electrolytes, Ce0.9(Bi0.09Mn0.005Fe0.005)O2 and Ce0.9(Bi0.1)O2, are selected and sintered to full density at 1050-1100 oC for 1 hr improved by doping trace amount of Mn and Fe The detail microstructure characterization of the doped samples are discussed.

Keywords: Ceria, Sintering, Conductivity, Bismuth, Iron, Manganese.