Estimate of Thermodynamic Indirect Measurement on the Electrocaloric Effect
The thermodynamics indirect measurement based on Maxwell relation is one of the most popular methods for the studies on electrocaloric effect of ferroelectric material, including bulk ceramics, single crystals and thin films. However, recent reports indicated that the results obtained through this method did not agree with those from the direct measurements in many cases, such as near Tc or under high electric field. This paper discussed the applicability of thermodynamics indirect measurement and analyzed the reason why its calculated result may be different from the true value of electrocaloric effect. Because the thermodynamics indirect characterization depends on the measurement of polarization at different temperatures, the testing frequency of P-E loops, leakage current of sample and temperature resolution of measurement play the important roles in the accuracy measurement of electrocaloric effect.
Yiwang Bao, Danyu Jiang, Li Tian and Jianghong Gong
K. Ding et al., "Estimate of Thermodynamic Indirect Measurement on the Electrocaloric Effect", Key Engineering Materials, Vol. 492, pp. 164-167, 2012