Dense ceramics of NaNbO3 produced from powders prepared by a new chemical route

The synthesis of a sodium niobate precursor by evaporation of a solution of an oxalato-niobium complex, sodium nitrate, oxalic acid and ammonium hydroxide, was studied using thermal analysis and XRD. Calcination of the precursor at temperatures above 500 C for 5 h in air yielded pure, single phase NaNbO3. The resulting powders were highly sinterable, and densities in excess of 95% of theoretical were achieved by sintering at 1250 C for 2 h in air. 55 refs.