Preparation and sintering behaviour of submicronic Bi4Ti3O12 powders

Submicronic powders of Bi4Ti3O12 With different morphologies were prepared by both the oxalate coprecipitation and the conventional mixing oxides methods. Compacts of the two calcined powders were sintered at 850-1100 degrees C in air, and the densification process was studied by non-isothermal and dilatometric experiments. A rapid densification (> 97% theoretical density) below 875 degrees C took place in the Bi4Ti3O12 oxalate powder which was attributed to an extremely uniform pore-size distribution in the green compact. The possible formation of a transient liquid which promotes densification also was taken into account. The development of plate-like morphology in the conventional Bi4Ti3O12 powder, broad pore-size distribution, and the plate-like colony formation, hindered rapid densification of the green compacts at low temperature. Microstructural development was studied; preliminary dielectric and electrical results are also reported.