Electrocaloric effect and energy storage in lead free Gd0.02Na0.5Bi0.48TiO3 ceramic

International audienceThe electrocaloric effect (EC) was investigated in the ferroelectric lead-free Gd0.02Na0.5Bi0.48TiO3 (GdNBT) ceramics. A pure perovskite structure was observed by the X-ray diffraction in GdNBT ceramics synthesized by a solid-state reaction method. Dielectric measurements revealed the existence of different ferroelectric and antiferroelectric transformations in this material. Based on the temperature dependence of P-E loops, reversible electrocaloric temperature changes of about Delta T = 0.75 K at the electric field of 90 kV/cm and the EC responsivity Delta T/Delta E approximate to 0.08 x 10(-6) K m V-1 were obtained in the GdNBT ceramics. The energy-storage density W = 0.85 J cm(-3) and the associated efficiency (eta = 65%) at 413 K were determined from the P-E loops data. The simultaneous existence of EC responsivity and energy-storage density makes GdNBT very promising lead-free material and opens a great potential for its application in electronic devices. (C) 2017 Elsevier Masson SAS. All rights reserved