Structural and dielectric properties of (Na0.5Bi0.5)0.70Ba0.30TiO3 ceramics

A (Na0.5Bi0.5)(0.70)Ba0.30TiO3 ceramic has been studied by X-ray diffraction and by measurements of dielectric and ferroelectric properties between room temperature and 450 degreesC. A sharp increase in the electric permittivity and dielectric loss near 200 degreesC has been observed. This sharp increase in dielectric responses indicates a transformation between normal and relaxor ferroelectric states. It is found that polar regions can exist at higher temperatures. The X-ray diffraction study shows that the transformation corresponds to the first order phase transition from tetragonal to cubic. The use of the (Na0.5Bi0.5)(0.70)Ba0.30TiO3 ceramic for device application has also been indicated. (C) 2003 Elsevier Science Ltd. All rights reserved.