2. Experimental methods for characterizing the electrocaloric effect

2.1 Direct methods

Direct measurement consists of directly measuring a thermal quantity when the electric field is applied, either the heat exchanged (enabling the entropy variation to be deduced), or the temperature variation. This type of characterization is essential for the future use of electrocaloric materials in cooling applications. However, these measurements are very tricky to set up, as the expected variations are usually very small and at the limit of the detection capacity of the equipment. As a result, experimental measurement errors of up to 10-20% of the measured value are common. In addition, it is difficult to control the thermal conditions applied to the sample, as the geometry of the sample determines the measurement frequency (high frequency (> 10 Hz) for pseudo-adiabatic...