Electrical properties of bismuth potassium titanate-strontium titanate ferroelectric ceramics

In this paper, lead-free (Bi0.5K0.5)TiO3 ceramics doped with SrTiO3 was prepared by the conventional solid state reaction method with sintering temperature at 1040°C. The samples were characterized by X-ray diffraction analysis and Scanning Electron Microscopy. The dielectric, ferroelectric properties were also investigated. The results of X-ray diffraction reveal that SrTiO3 diffuse into the Bi 0.5K0.5TiO3 lattices to form a solid solution with a pure perovskite structure. After the introduction of SrTiO3 into Bi0.5K0.5TiO3, the dielectric constant at room temperature (εr) was found to decrease with increasing SrTiO3. The broadness of the dielectric constant peak was observed with increasing SrTiO3 content, especially that of the 0.94Bi 0.5K0.5TiO3 - 0.06 SrTiO3 ceramic which exhibited a very broad curve over a wide temperature range. The Bi 0.5K0.5TiO3 - SrTiO3 system was expected to be a new and promising candidate for lead-free capacitors.