Sintering behaviors and dielectric properties of nanocrystalline barium titanate

Nanometer-scale barium titanate (BaTiO3) Powders were prepared via a process consisting of chemical dispersion and physical grinding/mixing. Sintering behaviors, microstructures as well as their correlations to dielectric properties of nano-BaTiO3 sintered at the temperatures ranging from 1100 to 1300 degrees C for various time spans were investigated. It was found that specific control on sintering condition is required for the nano-BaTiO3 powders to achieve desired microstructure, crystalline phase and dielectric properties of devices. The BaTiO3 sample sintered at 1100 degrees C for 6 h possesses relatively small grain sizes (about 140 nm), high density (about 95% T.D.) and distinct room-temperature dielectric properties (dielectric constant = 8000; dielectric loss = 5 x 10(-3)). Hence, in addition to the saving of thermal budget, the adoption of nano-scale ceramic powders in conjunction with appropriate sintering process may dramatically improve the dielectric properties of devices. (C) 2007 Elsevier B.V. All rights reserved.