Characterization and Sintering of Reactive Cerium(IV) Oxide Powders Prepared by the Hydrazine Method

Abstract

Nanocrystalline cerium(IV) oxide (CeO 2 ) powders have been prepared by adding hydrazine monohydrate to an aqueous solution of hydrous cerium nitrate (Ce(NO 3 ) 3 ·6H 2 O), followed by washing and drying. The lattice parameter of the as‐prepared powder is a = 0.5415 nm. The powder characteristics and sinterability of reactive CeO 2 have been studied. The surface areas of powders that have been heated at low temperatures are high, and these surface areas do not decrease to 10 m 2 /g until the temperature is >1200°C. Crystallite size and particle size are strongly dependent on the heating temperature. Optimum sintered densities are obtained by calcining in the temperature range of 700°–800°C. Ceramics with almost‐full density can be fabricated at a temperature as low as 1150°C.