Nanostructural and physical features of BaTiO3 ceramics prepared by two-step sintering

Nano-grained BaTiO3 ceramics were prepared using a two-step sintering process. The level of shrinkage and specific surface of the BaTiO3 green bodies were measured as a function of temperature. The two temperatures at which boundary diffusion and lattice diffusion begin to dominate were estimated by measuring the shrinkage behavior of the green bodies. These temperatures were used as the 1st- and 2nd-step temperature in this two-step sintering process. The BaTiO3 ceramics prepared from 20 nm-sized powders using the two-step sintering process at T1 = 1230 degrees C and T2 = 1160 degrees C (10 h) showed a relative mass density of similar to 91 % with very little variation in grain size compared with the starting powders. The ferroelectricity was determined from the local piezoelectric response behavior of the BaTiO3 ceramics with a grain size of 30 nm. The similar to 30 nm-size-grained ceramics showed considerable ferroelectric behavior. (C)2009 The Ceramic Society of Japan. All rights reserved.