A new effective method for direct electrocaloric measurements under arbitrary heat exchange conditions is proposed. The accuracy and reliability of the sample temperature measurements in dynamic provided by the use of mid-IR photodiode temperature sensors with the possibility of the in-situ calibration procedure

Temperature response of a material to an external electric field is the main method for electrocaloric effect study in ferroelectrics. In this work, for 0.65 PbFe2/3W1/3O3 – 0.35 PbTiO3 solid solution as a model object, it is shown that with an increase in the electric field strength, current filamentation effect can occur. It leads to formation of local regions of increased conductivity in the sample. The associated thermal effect have short characteristic times, due to the small volume of the filament. They are comparable to the times of the electrocaloric response of the material, and can lead to significant errors in the detection of the electrocaloric effect.