| CeO2 nanocrystallites were prepared by means of co-precipitation with cerium nitrate as the starting salts, ammonium carbonate as the precipitator and citric acid as the dispersant. Precursors and calcined powders were characterized using TEM,SEM,TGA and XRD. The results indicated that the morphology of precursors changed from nanowires to spherical particles with the increase of citric acid. The calcined CeO2 nanoparticles inherited obviously the morphology of precursors. The as-prepared CeO2 had the cubic crystal structure of fluorite, and the crystalline degree of samples increased with the roasting temperature.Ce0.8Sm0.2O2-α nanocrystallites were prepared with citric acid or polyethylene glycol as the dispersant. The precursors and calcined powders were characterized using TEM,SEM,and XRD. The results indicated that the as-prepared Ce0.8Sm0.2O2-α had the cubic crystal structure of fluorite; the morphology of precursors changed from nanowires to spherical particles with the increase of citric acid; Ce0.8Sm0.2O2-α nanowires changed shorter and finer with polyethylene glycol as the dispersant. The green compacts made from nanopowders were sintered at 1500℃. The oxygen ion conduction properties of ceramics were investigated by means of complex impedance, oxygen concentration cell at 6001000℃. It is found that the density of sinters is better when the temperature raise. The conductivities of sinter by addition of 5% polyethylene glycol than that of 1% polyethylene glycol.
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