Nano-sized Bi4Ti3O12 powder prepared by the hydrolysis process

Nano-sized Bi4Ti3O12 powders were prepared by hydrolyzing Bi(NO3)(3).5H(2)O and Ti(OC4H9)(4) in acidic water. Bi4Ti3O12 began to crystallize from the amorphous precursor at 500degreesC together with an intenmediate phase of Bi2Ti2O7. Pure Bi4Ti3O12 Crystalline phase was formed after half an hour aging at 600degreesC, 200degreesC lower than the formation temperature of Bi4Ti3O12 by solid-state reaction between Bi2O3 and TiO2. The as-prepared powder showed a high specific surface area Of 95m(2)/g with increasing temperature, the specific surface area declined due to the increasing particle size and crystallinity of the powder. At 600degreesC, the specific Surface area dropped to 12 m(2)/g. TEM revealed that the as-prepared bismuth titanate precursor consisted of well-dispersed particles of about 10nm, while Bi4Ti3O12 powder with a particle size of about 100 nm was formed after calcined at 600degreesC. This powder was almost aggregate-free and could be almost fully densified by sintering at 950degreesC for 1h, showing excellent sinterability.