Entropy-change measurement of electrocaloric effect of BaTiO3 single crystal

We demonstrated a characterization method of entropy-change measurement for the study of the electrocaloric effect (ECE). After the specific heat capacity was measured under different applied fields using a differential scanning calorimeter (DSC) accompanied with DC power supply, the electrocaloric Delta S was calculated from the temperature integral of specific heat capacities based on the basic definition of entropy. The Delta S-T curve of BaTiO3 single crystal showed a sharp peak around T-c, which increased gradually and shifted to higher temperature with the rise of applied field. A high ECE with Delta S=1.9 J/kg K and Delta T=1.6 K is achieved under a quite low field of 10 kV/cm. The results agreed with the thermodynamic calculation. It provides a direct, precise, and time-efficient method for the electrocaloric studies. (c) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim