Antiferroelectric (AFE) materials have a tremendous advantage as smart materials and large-strain actuators due to their unique reversible characteristic electric-field-induced strain (electrostrain) responses in comparison to piezoelectric effect and electrostriction. A key limitation to today's AFE actuators, however, is the poor temperature stability of electrostrain. In this work, a large reversible strain of 0.4% and an excellent thermal stability with a variation within ±5.5% from 20 to 190 °C were achieved for (Pb0.97La0.02)(Zr0.85Sn0.08Ti0.07)O3 (PLZST) AFE ceramics. A room-temperature electrostrain of 0.71% was obtained in virgin PLZST ceramics. It is intriguing to observe inconsistent strain curves between the first and further measured cycles, implying an incomplete reversible field-induced AFE-ferroelectric phase transition. A sharp electrostrain response in milliseconds was realized in the as-prepared PLZST ceramics. In addition, a phenomenological explanation was proposed to explain the extraordinary phenomena. Our results may shed light on the origin of the superior strain behaviors in AFE materials from the view of microscopic structure and macroscopic properties, and probably improve the understanding of the AFE phase transition.
Keywords: PLZST; antiferroelectric ceramics; electrostrain; reversible phase transition; temperature stability.