Room temperature electrocaloric effect on PbZr0.8Ti0.2O3 thin film

Abstract

A phase field model based on the time-dependent Ginburg–Landau equation (TDGL) is developed to investigate the electrocaloric effect (ECE) of PbZr0.8Ti0.2O3 (PZT) thin film with a multidomain structure. The rhombohedral domain morphology is obtained through numerically solving the TDGL equation with periodic boundary conditions at room temperature. Then the ECE of PZT thin film is investigated by the thermodynamics analysis. It is shown that a great ECE exists with an applied ac electric field at room temperature. The magnitude of ECE greatly depends on the external applied electric field and becomes a periodic time-dependent quantity. The theoretical calculations also reveal that both compressive and tensile misfit strains caused by the mismatch between the film and the substrate can largely affect the electrocaloric properties. It reveals that the compressive substrate strain enhances the ECE of PZT thin film while the tensile substrate strain suppresses it.