Introducing vacancy defects to induce ferroelectric-like switching in antiferroelectric oxides

Abstract

The electric field-induced antiferroelectric to ferroelectric transition in lead zirconate-based antiferroelectric materials has been explored for actuator, sensor and energy storage applications. The critical electric field required for the transition to the ferroelectric phase is the determining factor for the performance of antiferroelectric materials in practical applications. A way to decrease the critical electric field is chemical modification with isovalent (Ti⁴⁺) or donor (La³⁺, Nb⁵⁺) substituents. Here, we show that it is also possible with acceptors. We found this possibility while investigating Pb_0.995(Zr_0.53Sn_0.47−yTi_y)_0.99Nb_0.01O₃, with y = 0.07, a polycrystalline ceramic of typical antiferroelectric composition and its acceptor (Fe³⁺)-doped compositions. We closely examined its field-induced polarization switching as well as structural transitions. We found ferroelectric-like polarization switching at a particular acceptor concentration with a substantial reduction in critical electric field. We demonstrate that such unexpected ferroelectric-like switching in an antiferroelectric ceramic is brought about and regulated by point defects that are formed during the acceptor-doping as part of charge compensation.