The giant electrocaloric effect and high effective cooling power near room temperature for BaTiO₃ thick film

Abstract

The electrocaloric effect (ECE) of BaTiO₃ multilayer thick film was investigated by direct calorimetric measurement. The ECE increases monotonically with the enhancement of applied field. The maximum ECE occurs above T[sub c] and shifts to higher temperature with increasing applied field. Under an ultrahigh field of 800 kV/cm, it exhibits a giant ECE of ΔT = 7.1 K and ΔS = 10.1 J/kg · K at 80 °C. The ECE heat follows a general power-law relation with the varying rate of applied field within a certain range. A high cooling power (∼50 W/kg) is achieved based on the net-cooling resulting from the different varying rates of rising and falling fields.