Enhanced electrocaloric response and high energy-storage properties in lead-free (1-x) (K0.5Na0.5)NbO3 - xSrZrO(3) nanocrystalline ceramics

Recently electrocaloric effect in lead-free environmental friendly ferroelectrics is in its peak research. The feasible and existed electrocaloric response in lead-free (1-x) (K0.5Na0.5)NbO3 - xSrZrO(3) (KNN-xSZ) nanocrystalline ceramics is demonstrated using Maxwell's thermodynamic approach. The maximum electrocaloric response of 1.19 K at 367 K was observed under the electric field of 35 kV/cm, and the corresponding electrocaloric responsivity value was found to be 3.40 x 10(-7) K m/V at 367 K for x = 0.10. A significant coefficient of performance (COP) and electrical energy storage density (W-rec) were calculated to be 0.62 and 0.20 J/cm(3), respectively. The atomistic mechanism of the electrocaloric effect is discussed. The results indicate that KNN-xSZ is a favourable material in the cooling system applications and energy-storage for electronic devices. The material allows electrocaloric cooling mode with versatile properties for the cooling operation by an external electric field and operating temperature. (C) 2018 Elsevier B.V. All rights reserved.