Effects of tungsten doping on the sintering and properties of strontium bismuth tantalate ceramics

The effects of tungsten doping on the sintering, microstructure, dielectric properties, and ferroelectric properties of SrBi2(Ta1-xWx)O9+y ceramics were investigated. The densification and grain-growth processes of the tungsten-doped ceramics were shifted to a lower temperature range. For the ceramics with relative density greater than or equal to90%, the dielectric constant is 120-125 and 80-170 for the undoped and doped ceramics, respectively, and the dielectric loss tangent is below 2%. As compared with the undoped ceramics, the ferroelectric properties can be significantly improved by doping with an appropriate amount of tungsten (x = 0.05-0.1) and sintering at 1000-1200degreesC. The variations of dielectric and ferroelectric properties are influenced by the incorporation of tungsten into crystal lattice and several microstructural factors.