The Influence of Measurement Conditions on the Electrocaloric Effect in Ferroelectric Ceramics of Modified Barium Titanate.

In this work, the electrocaloric effect (ECE) and electrocaloric strength (Δ T / E ) were measured and thermal and dielectric studies were performed on Pb-modified BaTiO 3 (BPT). The saturated hysteresis loops and normal ferroelectric behavior of the ferroelectric ceramics allow the utilization of the indirect method to estimate the electrocaloric properties. The electrocaloric measurements were performed under high (18 kV/cm) versus low (8 kV/cm) electric field conditions. These conditions were chosen to notice and then eliminate an artificial negative electrocaloric effect in the tested ceramics. At the same time, relatively high values of positive electrocaloric temperature change Δ T (~ 2.19 K) and electrocaloric strength Δ T / E (~0.27-0.11 K·cm/kV) were obtained.