Properties of tungsten-doped Bi4Ti3O12-SrBi4Ti4O15 intergrowth ferroelectrics

Ferroelectric and dielectric properties of tungsten-doped Bi4Ti3O12-SrBi4Ti4O15 ceramics were investigated. A pure phase of all the samples is confirmed by X-ray diffraction patterns. The remanent polarization (2Pr) of the samples increases initially and reaches its maximum value of 43.2 μC/cm2 when W content is 0.03, which is over twice as large as that of non-doped one, then decreases with further doping. The coercive field (Ec) shows a weak tungsten content dependency. It is considered that the enlarged 2Pr could be mainly attributed to the restraint of oxygen vacancies as well as the weakening of their mobility. The Curie temperature decreases a little with increasing doping content, which indicates the good thermal stability is not deteriorated by tungsten doping.