Interfacial coupling modulation to the electrocaloric effect of Ba(Zr, Ti)O3 multilayered thick films

Abstract

Negative environmental consequences of traditional cooling technologies have spurred the development of newly emerged green cooling devices rooting in electrocaloric effect (ECE). The relaxor ferroelectrics represented by BaZrTiO3 ceramics are being actively explored as a promising candidate for constructing ECE cooling devices. However, the reported electrocaloric (EC) response of BaZrTiO3 is still limited, particularly under low and moderate electric fields, which greatly inhibits its practical application. In this work, we propose an interfacial coupling modulation approach to enhance the EC response of BaZrTiO3 by introducing composition homogeneous and composition gradient multilayered structures. A systematic work was performed to study the dielectric, ferroelectric, and EC performances of BaZrTiO3 multilayered ceramics consisting of BaZr0.20Ti0.80O3 and/or BaZr0.17Ti0.83O3. It was found that the optimized BaZr0.17Ti0.83O3/BaZr0.20Ti0.80O3 bilayered films displayed the maximum EC response of 4.1 K under 10 MV m−1 at ambient conditions, corresponding to a high level of the coefficient of performance up to 18.33. The results demonstrate the efficiency of interfacial coupling modulation in boosting the EC response of relaxor ferroelectric ceramics, opening up an avenue to explore advanced electrocaloric systems with a giant electrocaloric effect.