Preparation and properties of SrBi2Ta2O9 ceramics II

The purpose of this study is to investigate the preparation and properties of two types of SrBi2Ta2O9 ceramics, SrBi2Ta2O9 ceramics with excess Bi2O3, and two-phase ceramics formed with SrBi2Ta2O9 and BiTaO4. The samples were prepared by a conventional ceramic technique at 900 to 1300 degreesC for 2 h, The optimum firing temperature for ceramics with excess Bi2O3 was about 1000 degreesC when Bi2O3 was added in the amount of 0.75 wt%. The Curie te mperature T-c of the two types of samples varied between 302 degreesC and 4 40 degreesC. The substitution in SrBi2Ta2O9 was estimated from the change o f T-c. The values of the dielectric constant and remanent polarization for the two-phase ceramics, SrBi2Ta2O9/BiTaO4, were greater than those of SrBi2 Ta2O9 ceramics.