Characterization and sintering of nanocrystalline CeO2 powders synthesized by a mimic alkoxide method Original Research Article

Nanocrystalline CeO2 powders of high sinterability have been successfully synthesized by a mimic alkoxide method, which employs alcohols as solvent, cerium nitrate hexahydrate as cerium source and diethylamine (DEA) as precipitant. Precipitation participating anions (OH−) are generated via the hydrolysis of DEA with the molecular water of the cerium salt. Irrespective of solvent type, the precursors produced by this method are CeO2·2H2O, which completely dehydrates to CeO2 at temperatures >500°C. Calcining the precursors at 600°C for 2 h yields highly reactive CeO2 powders with average crystallite sizes of ∼15 nm. These powders can be densified to >99% of the theoretical up to 1160°C in air at a constant heating rate of 10°C/min or to the same density by isothermal sintering at 1000°C for 2 h. The effects of calcination temperature and solvent type on powder characteristics and sinterability are also investigated.