Antiferroelectric-ferroelectric phase transitions in Pb1−xBaxZrO3 ceramics: Effect of PbO content

The irreversibility of the antiferroelectric (AFE) to FE phase transition in Pb1−xBaxZrO3, x=0.75–0.1, compositions is shown to be a consequence of lattice vacancies arising from PbO evaporation during ceramic processing. Previously, the absence of a FE→AFE cooling transition was thought to be due to the transformational strain and the fragmentation of ferroelectric domains. Appropriate compensating levels of excess PbO added to starting powders generate the FE→AFE transition. For lower levels of Ba2+ substitution, x=0.05, the transition is reversible in noncompensated samples, but PbO compensation raises the FE→AFE transition temperature by ∼25°C.