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 (2P_r) 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 (E_c) shows a weak tungsten content dependency. It is considered that the enlarged 2P_r 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.