Direct measurement of giant electrocaloric effect in BaTiO3 multilayer thick film structure beyond theoretical prediction

Abstract

The electrocaloric (EC) effect of ${\text{BaTiO}}_3$ multilayer thick film structure was investigated by direct measurement and theoretical calculation. The samples were prepared by the tape-casting method, which had 180 dielectric layers with an average thickness of $1.4\mu \text{m}$ . The thermodynamic calculation based on the polarization-temperature curves predicted a peak heat adsorption of 0.32 J/g at $80°\text{C}$ under 176 kV/cm electric field. The direct measurement via differential scanning calorimeter showed a much higher EC effect of 0.91 J/g at $80°\text{C}$ under same electric field. The difference could result from the different trends of changes of electric polarization and lattice elastic energy under ultrahigh electric field.