Dielectric Properties of the Mixed Aurivillius Phases M~(II)Bi_8Ti_7O_(27) (M~(II) = Ca, Sr, Ba and Pb)

摘要

Ceramic materials have been prepared by natural sintering and hot-forging M~(II)Bi_8Ti_7O_(27)(M~(II) = Ca, Sr, Ba and Pb) powders synthesized using a molten salt technique. The materials are ferroelectric at room temperature and show strong dielectric anisotropy in connection with the crystal structure. In each case, a double anomaly of the dielectric permittivity was found as a function of temperature. The temperatures at which it occurs are dependent on M~(II). The origin of this phenomenon is assumed to be closely related to a sequence of phase transitions like those already observed in other mixed Aurivillius phases.