  The electrocaloric effect of BaTiO3 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 m. The thermodynamic calculation based on the
polarization- temperature curves predicted a peak heat adsorption of 0.32J/g at
80^\circC under 176kV/cm electric field. The direct measurement via
differential scanning calorimeter showed a much higher electrocaloric effect of
0.91J/g at 80^\circC 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.
