Giant shape memory and domain memory effects in antiferroelectric single crystals†
We report irreversible and reversible antiferroelectric–ferroelectric phase transitions, shape memory and domain memory effects in (Pb,La)(Zr,Sn,Ti)O3 antiferroelectric tetragonal single crystals. We find that electric-field-induced antiferroelectric to ferroelectric phase transition is an irreversible process at temperatures below the depolarization temperature (∼50 °C), and achieves a giant shape memory strain value of 0.70% at room temperature. With the help of an in situ polarized light microscope, we discover a reversible phase transition between antiferroelectric and ferroelectric phases and a domain memory effect during electric field cycling above the depolarization temperature. In addition, single crystal X-ray diffraction results reveal that field-induced transformations between incommensurate antiferroelectric and commensurate ferroelectric modulations enable the emergence of shape and domain memory effects. A physical picture is proposed to explain these phase-transformation-mediated memory effects. Their discovery is expected to stimulate a systematic research upsurge of domain engineering and structure–property relationships in the quest for developing new antiferroelectric or ferroelectric devices.