Electrocaloric effect in BaTiO3 based lead-free multilayer ceramic capacitors

The electrocaloric effect (ECE) of multilayer ceramic capacitor (MLCC) of Y5V type was directly measured via a differential scanning calorimetry (DSC) method and a reference resistor was used to calibrate the heat flow due to the heat dissipation. The results are compared with those calculated from Maxwell relations by using the polarization data obtained from the polarization - electric field hysteresis loops. The direct method shows a larger ECE temperature change, which is accounted for the situation approaches an ideal condition. For the indirect method using Maxwell relations, only the polarization projection along the electric field was taken into account, which will be less than the randomly distributed real polarizations that contribute to the ECE. The MLCCs exhibit a broad peak of ECE around 80 °C, which will be favorite for the practical ECE cooling devices.