Sintering behaviors of bismuth titanate synthesized by a coprecipitation method

Ultrafine bismuth titanate (BiT) powder has been fabricated by a coprecipitation method. It is found that sintering behaviors of BiT strongly depend on the calcination temperature of precursor. The calcination temperature of 450 degrees C below crystallization is high enough to decompose most of BiT precursor to avoid the cracks in sintered samples, and also low enough to ensure high sinterability, which facilitates the densification of BiT ceramics. Additionally, the crystallization of amorphous powders during the process of sintering also contributes to an enhancement in densification. BiT ceramic with the relative density >95% can be obtained at a temperature as low as 825 degrees C from the powder calcined at 450 degrees C. (C) 2005 Elsevier B.V. All rights reserved.