Magnetocaloric effect and piezoresponse of engineered ferroelectric-ferromagnetic heterostructures

This study reports the magnetocaloric effect (MCE) and piezoresponse of integrated ferroelectric-ferromagnetic heterostructures of PbZr _0.52Ti _0.48O ₃ (PZT) (5 nm)/Bi-Sr-Ca-Cu ₂-O _X (BSCCO) (5 nm)/La _0.67Sr _0.33MnO ₃ (LSMO) (40 nm)/MgO (0 0 1). Magnetic and pizoresponse behavior of the heterostructures are found to be governed by magneto-electric coupling and induced lattice strains. In addition, a maximum MCE is studied using Maxwell equations from both Field Cooled (FC) and Zero Field Cooled (ZFC) magnetization data. Maximum MCE entropy change (|ΔS|) of 42.6 mJkg ⁻¹K ⁻¹ (at 258 K) and 41.7 mJkg ⁻¹K ⁻¹ (at 269 K) are found corresponding to FC and ZFC data, respectively. The variation in maximum entropy change and corresponding temperatures for FC and ZFC data revealed that the application of a magnetic field can significantly contribute towards tuning of the MCE. Interestingly, these multilayered structures are found to sustain MCE over a broad temperature range, which makes them attractive for improved solid-state energy conversion devices.