The coexistence of the negative and positive electrocaloric effect in ferroelectric thin films for solid-state refrigeration

The coexistence of the negative and positive electrocaloric effect (ECE) caused by an applied electric field direction different from the dipole direction of 180 degrees domain structures is firstly found in ferroelectric thin films using the phase-field-based simulation. The calculation results reveal that a negative adiabatic temperature change (Delta T = -3.4K) and a positive adiabatic temperature change (Delta T = 3.1K) coexist in the PbTiO3 thin film with 180 degrees domain structures under the dimensional electric field Delta E = 0.1. The coexistence of negative and positive ECE in a thin film can provide a new way to design solid-state refrigerators. Copyright (C) EPLA, 2013