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

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-c and shifts to higher temperature with increasing applied field. Under an ultrahigh field of 800 kV/cm, it exhibits a giant ECE of Delta T-7.1 K and Delta S-10.1 J/kg.K at 80 degrees 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 (similar to 50 W/kg) is achieved based on the net-cooling resulting from the different varying rates of rising and falling fields. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3658251]