Interrelation of electrocaloric and concomitant effects in lead magnesium niobate based ceramics

Electrocaloric effect (ECE) as well as field induced pyroelectric and piezoelectric effects were investigated in relaxor ceramics 0.84 PbMg1/3Nb2/3O3–0.14 PbTiO3–0.02 SrTiO3. Dielectric and elastic properties of the solid solution were also studied. To improve the accuracy and reliability of the results obtained, the electrocaloric temperature change δT was measured both by the well-known quasi-adiabatic technique with a contact temperature sensor and by the radiometric mid Infrared technique developed by the authors. The contribution of the secondary pyroelectric effect to the total pyroelectric and ECE was studied in detail. The effect of the induced piezoelectricity on the range of the temperature stability of pyroelectric and electrocaloric responses was shown. The resulting combination of material parameters at reasonable operating temperatures and electric fields, including both the possibility of increasing δT and the existence of its temperature-independent range from 10 to 80 °C, predestines the solid solution as a promising electrocaloric material.