Enhanced magnetoelectric coupling in environmental friendly lead-free Ni0.8Zn0.2Fe2O4-Ba0.85Ca0.15Zr0.1Ti0.9O3 laminate composites

Lead-free piezomagnetic-piezoelectric, Ni0.8Zn0.2Fe2O4(NZFO)-Ba0.85Ca0.15Zr0.1Ti0.9O3(BCZT) laminate composites featuring improved magnetoelectric (ME) properties are reported. The solid-state method has been used for the synthesis of NZFO and BCZT. Sintered layers were laminated using silver epoxy with a 2-2 connectivity scheme. The refined profiles of X-ray diffraction patterns support the coexistence of tetragonal and rhombohedral phases in BCZT and spinel cubic phase in NZFO. Scanning electron microscopy with elemental mapping revealed prepared sample's surface morphology and chemical composition. BCZT exhibited a high value of dielectric constant at T-C (epsilon similar to 11,200 at 100 Hz), the significant value of electromechanical coupling factor (K-P similar to 51.2%), and well-saturated polarization (P) vs applied electric field (E) loops. Ferri-magnetic NZFO also exhibits a large value of saturation magnetization (M-S similar to 62.10 emu/g), and plot between the derivative of the square of magnetization (dM(2)/dH) vs applied magnetic field (H) follows the same trend as that of observed field-dependent ME coupling coefficient for layered composites. The layered composites demonstrated low leakage current and high dielectric constant, which further favours stronger ME coupling. At lower magnetic fields, tri-layer (NZFO/BCZT/NZFO) and bi-layer (BCZT/NZFO) laminate composites respond with ME coupling coefficients alpha(ME) similar to 600 mV/cm-Oe and 128 mV/cm-Oe, respectively, making them excellent lead-free material for future multifunctional devices.