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

Abstract Nanocrystalline CeO 2 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 CeO 2 ·2H 2 O, which completely dehydrates to CeO 2 at temperatures >500°C. Calcining the precursors at 600°C for 2 h yields highly reactive CeO 2 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.