Origin of large negative electrocaloric effect in antiferroelectric PbZrO3
P. Vales-Castro, R. Faye, M. Vellvehi, Y. Nouchokgwe, X. Perpina, J.M. Caicedo, X. Jorda, K. Roleder, D. Kajewski, A. Perez-Tomas, E. Defay, and G. Catalan
Physical Review B, vol. 103, no. 5, 2021
We have studied the electrocaloric response of the archetypal antiferroelectric PbZrO3 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 -3.5 K to an electroheating of +5.5 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.