Magnetocaloric effect and piezoresponse of engineered ferroelectric-ferromagnetic heterostructures

Abstract

Present study reports the magnetocaloric effect (MCE) and piezoresponse of integrated ferroelectric-ferromagnetic heterostructures of PbZr0.52Ti0.48O3 (PZT) (5 nm)/ Bi-Sr-Ca-Cu2-OX (BSCCO) (5 nm)/ La0.67Sr0.33MnO3 (LSMO) (40 nm)/ MgO. Magnetic and pizoresponse behavior of the heterostructures are found to be governed by magneto-electric coupling and induced lattice strains. In addition, the MCE is studied using Maxwell equations from both Field Cooled (FC) and Zero Field Cooled (ZFC) magnetization data. Maximum MCE entropy change (|∆S|) of 42.6 mJkg -1 K -1 (at 258 K) and 41.7 mJkg -1 K -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.

Domain Switching in BaTiO3 Films Induced by an Ultralow Mechanical Force

“…Mechanical switching has been reported in a series of ferroelectric materials, such as BiFeO 3 , 17−19 BaTiO 3 , 10,20 (1 − x)Pb(Mg 1/3 Nb 2/3 )O 3 -xPbTiO 3 (x = 0.32, 0.40), 21 (Zr 0.2 Ti 0.8 )O 3 , 22 PbZr 0.48 Ti 0.52 O 3 . 23 The flexoelectric effect on ferroelectric polarization was investigated by regulating the lattice mismatch with the substrates, 4 oxygen vacancy, 7,24,25 and deposition temperature 26 during the film growth and bending the substrate directly. 27 Many strategies have been conducted to decrease the threshold force of ferroelectric domain switching.…”

“…(a) The threshold force for mechanically induced single-domain inversion in several ferroelectric films reported to date. (b) Relationshipbetween threshold force and in-plane strain 10,19,23,28,29.…”

Study of electro-elastocaloric effect and pyroelectric energy density in piezocomposites

“…Piezocomposites contain piezoelectric materials as the fibre phase and a passive material (epoxy) as the matrix phase. Piezocomposites are predominantly used in the actuator, vibration control, energy harvesting and cooling applications [2,[5][6][7][8][9][10][11][12][13][14][15][16][17].…”

“…Due to low phase-transition temperature of ferromagnetic materials, extensive studies have been carried out for magnetocaloric effect with their applications in solid-state ferromagnetic refrigeration devices [14,18,19] as compared to electrocaloric effect (ECE). Though ferromagnetic materials can produce giant cooling effect near room temperature [20,21], it requires a strong magnetic field.…”

Low‐Pressure Mechanical Switching of Ferroelectric Domains in PbZr0.48Ti0.52O3

“…[1 ] In a related attempt Edwards et al [6] reported the mechanical switching threshold (1000 nN: estimated tip pressure = 0.8 GPa; tip radius = 20 nm) of polycrystalline PbZr 0.53 Ti 0.47 O 3 , which lays at the morphotropic phase boundary (MPB) of the Pb(Zr x Ti (1−x) )O 3 family. Compositions close to the MPB of Pb(Zr x Ti (1−x) )O 3 offer the possibility of transitions between tetragonal and rhombohedral phases due to small strains [27][28][29][30][31] as well as the co-existence of tetragonal and rhombohedral phases, [5,32] and have been investigated with respect to thickness-dependent flexoelectric fields, [32] making them ideal for pressure-induced polarization switching. Therefore, in this work, we explore the ferroelectric and mechanical Figure 1a shows the room temperature (297 K) HR-X-ray diffraction (XRD) patterns of the PZT/YBCO/LAO heterostructures.…”