Effect of synthesis method upon the dielectric properties of SrBi2Ta2O9

SrBi2Ta2O9 (SBT) powders were prepared by three different methods: solid-state reaction, sol-gel, and gel-casting method. A and their effects upon the sintering behavior and dielectric properties of SBT were investigated. The results show that among the three methods the synthesis temperature of sol-gel is the lowest and the synthesized particle size is also the smallest, which is about 60 nm. However, for gel-casting, the obvious aggregation can be found in its prepared powders, which may result from its higher synthesis temperature and relatively low melting point of Bi2O3. This contributes to its relatively lower sintering ability. Compared with the other two synthesis methods, lower density can be obtained under the same sintering conditions. Further studies show that different synthesis methods also have close relations to the dielectric properties of SBT.