Powders of Samaria, Yttria doped ceria and co-doped with iron were synthesized by hydrothermal method. The iron content for all the investigated compositions is 0.5 wt. %. The powders were investigated by thermogravimetric analysis (TGA) X-ray diffraction (XRD), Infrared (IR), Transmission electron microscope (TEM) and Raman specra. The effect of autoclaving time on the crystallinity was studied. The powders were impacted and sintered at different temperatures. The density and linear shrinkage were investigated for all sintered bodies. XRD revealed that the powders crystallize in fluorite centered cubic structure with the improvement in crystallinity. The presence iron in the solid solution lowered the degree of crystallinity. TEM images for the co-doped powders displayed semi-rounded nano-sized particles with narrow size distribution. It is concluded that the optimum fluorite structure for solid solutions is obtained with 10 mol % Samaria doped ceria (10SDC)Fe and iron codoped 10 mol % Yttria doped ceria (10YDC) Fe samples.