Preparation of Bi4Ti3O12 ceramics via a high-energy ball milling process

Nano-sized bismuth titanate (Bi4Ti3O12) powders were prepared by a high-energy ball milling process directly from their oxide mixture of Bi2O3 and TiO2. Bi4Ti3O12 phase can be formed from the oxide mixture after milling for 9 h. Almost single phase of Bi4Ti3O12 is obtained after milling for 15 h. With increasing milling time, the particle size of the mixture is gradually reduced. Bi4Ti3O12 ceramics were obtained by sintering the synthesized powders at temperatures ranging from 750 degreesC to 950 degreesC. The Bi4Ti3O12 ceramics sintered at 850 degreesC for 1 h exhibited a density of 7.91 g/cm(3), a dielectric of 243 and a dielectric loss of 0.017, and a remnant polarization of 24 muC/cm(2) and a coercive field of 11 kV/cm, respectively. Piezoelectric parameters of the Bi4Ti3O12 ceramics are k(33) = 56%, k(31) = 58%. The Bi4Ti3O12 ceramics also possessed good pyroelectric properties, These results indicate that high-energy ball milling process is a promising way to prepare Bi4Ti3O12 ceramics. (C) 2001 Elsevier Science B.V. All rights reserved.