Sintering and decomposition of ferroelectric layered perovskites: Strontium bismuth tantalate ceramics
Resource
Journal of the European Ceramic Society 19 (16): 2909-2915
Journal
Journal of the European Ceramic Society
Journal Volume
19
Journal Issue
16
Pages
2909-2915
Date Issued
1999
Date
1999
Author(s)
Chen, Yi-Chou
Abstract
The sintering behavior of layered-type perovskite ferroelectric ceramics SrBi2Ta2O9 has been investigated in this study. Pure SrBi2Ta2O9 powder is difficult to sinter at low temperatures. Raising the sintering temperature induces an increase in the density of SrBi2Ta2O9, and also causes its thermal decomposition, thereby resulting in the formation of a secondary phase-SrTa2O6. On the other hand, adding excess amounts of Bi2O3 (≥2 mol%) in SrBi2Ta2O9 facilitates the densification process and suppresses the decomposition reaction. SrBi2Ta2O9 ceramics with a density higher than 95% theoretical have been successfully prepared after sintering at 1100°C. The microstructure and crystallographic orientation are significantly influenced by the sintering temperature as well as the amount of Bi2O3 addition. Increasing the amount of Bi2O3 and sintering temperature enhances the development of the preferred orientation along the c-axis and the coarsening of grains. The occurrence of the c-axis preferred orientation is ascribed to anisotropic grain growth. © 1999 Elsevier Science Ltd.
Type
journal article