Grain orientation and properties of SrBi2Ta2O9 ceramics with excess Bi2O3

Abstract

The purpose of this paper is to investigate the grain orientation and properties of SrBi2Ta2O9 (SBT) ceramics with excess Bi2O3. Ordinarily fired (OF) ceramics were prepared by conventional ceramic techniques at 900–1300°C for 2 h. The grain-oriented (GO) ceramics were prepared using the hot-forging method. With addition of Bi2O3 in the amount of 0 – 1.5 wt% to the SBT of stoichiometric composition, the optimum firing temperature in OF ceramic samples gradually lowered with increasing Bi2O3 addition, and was about 1100°C in the case of 0.5 wt% of excess Bi2O3. Plastic deformation is easily accomplished using the hot forging method where Bi2O3 exists as a state of liquid phase within the sample. In fact, the GO sample with 0.5 wt% of excess Bi2O3 showed a highly structured orientation f=0.97 in the case of hot-forging at 1100°C.