Origin of large negative electrocaloric effect in antiferroelectric <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>PbZr</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math>
Pablo Vales‐Castro, Romain Faye, M. Vellvehı́, Youri Nouchokgwe, X. Perpiñà, José Manuel Caicedo, X. Jordà, Krystian Roleder, Dariusz Kajewski, Amador Pérez‐Tomás, Emmanuel Defaÿ, Gustau Catalán
Abstract
We have studied the electrocaloric response of the archetypal antiferroelectric $\mathrm{PbZr}{\mathrm{O}}_{3}$ as a function of voltage and temperature in the vicinity of its antiferroelectric-paraelectric phase transition. Large electrocaloric effects of opposite signs, ranging from an electrocooling of \ensuremath{-}3.5 K to an electroheating of $+5.5\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, were directly measured with an infrared camera. We show by calorimetric and electromechanical measurements that the large negative electrocaloric effect comes from an endothermic antiferroelectric-ferroelectric switching, in contrast to dipole destabilization of the antiparallel lattice, previously proposed as an explanation for the negative electrocaloric effect of antiferroelectrics.