The Antiferroelectric ↔ Ferroelectric Phase Transition in Lead‐Containing and Lead‐Free Perovskite Ceramics

A comprehensive review on the latest development of the antiferroelectric ↔ ferroelectric phase transition is presented. The abrupt volume expansion and sudden development of polarization at the phase transition has been extensively investigated in PbZrO 3 ‐based perovskite ceramics. New research developments in these compositions, including the incommensurate domain structure, the auxetic behavior under electric fields in the induced ferroelectric phase, the ferroelastic behavior of the multicell cubic phase, the impact of radial compression, the unexpected electric field‐induced ferroelectric‐to‐antiferroelectric transition, and the phase transition mechanical toughening effect have been summarized. Due to their significance to lead‐free piezoelectric ceramics, compounds with antiferroelectric phases, including NaNbO 3 , AgNbO 3 , and ( Bi 1/2 Na 1/2 ) TiO 3 , are also critically reviewed. Focus has been placed on the ( Bi 1/2 Na 1/2 ) TiO 3 – BaTiO 3 solid solution where the electric field‐induced ferroelectric phase remains even after the applied field is removed at room temperature. Therefore, the electric field‐induced antiferroelectric‐to‐ferroelectric phase transition is a key to the poling process to develop piezoelectricity in morphotropic phase boundary ( MPB ) compositions. The competing phase transition and domain switching processes in 0.93( Bi 1/2 Na 1/2 ) TiO 3 –0.07 BaTiO 3 are directly imaged with nanometer resolution using the unique in situ transmission electron microscopy ( TEM ) technique.