Nano-crystalline fluorite-like structure CeO2 and Ca-doped CeO2 compounds were prepared in the temperature range of 220-400 degrees C using a precursor method which involves coprecipitation of Ca2+ and Ca4+ ions using oxalic acid from the aqueous calcium chloride and ammonium cerium nitrate solutions. The precipitated products were characterized by employing thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), infrared spectroscopy JR), laser particle size analysis (LPSA) methods and scanning electron microscopy (SEM). TGA studies show two step weight loss in the temperature range: (i) room temperature to 200 degrees C and (ii) 200-400 degrees C for all the investigated precursors. The former loss is attributed to loss of water while the latter is due to dicomposition of oxalates. The XRD study reveal a complex pattern for the as-precipitated powders, and surprisingly we see the formation of single-phase fluorite-like structure at about 220 degrees C for Ce1-xCaxO2-x (O

Keywords:Ca-doped CeO2;coprecipitation;Ce1-xCaxO2-x;soft-chemical synthesis;nano-particles;oxide ion electrolyte