Magnetoelectric response in lead-free Na<inf>0.4</inf>K<inf>0.1</inf>Bi<inf>0.5</inf>TiO<inf>3</inf>/NiFe<inf>2</inf>O<inf>4</inf> laminated composites

Lead-free Na0.4K0.1Bi0.5TiO3 (NKBT) and NiFe2O4 (NFO) ceramics are synthesized by solid-state reaction, and the laminated NKBT/NFO composites have been prepared by gluing the sintered discs with silver-epoxy. The measured parameters, dielectric constant (ε′) ∼1450 at 1 kHz, remanent polarization (Pr)∼39 μC/cm2, coercive electric field (Ec)∼27 kV/cm and maximum strain (Smax)∼0.3 % of NKBT along with saturation magnetization (Ms)∼49 emu/g, coercive magnetic field (Hc)∼27 Oe and magnetostriction (λ)∼-30 ppm of NFO, makes them suitable materials to evaluate as laminated magnetoelectric (ME) composites. A maximum ME response of 37, 67 and 86 mV/cm Oe at Hdc∼350−400 Oe field and 1 kHz frequency is observed for NKBT/NFO, NKBT/NFO/NKBT and NFO/NKBT/NFO layered composites, respectively. The high ME response at reasonable fields implies that NKBT/NFO laminated composite is a worthy lead-free candidate for ME sensor and energy harvesting applications.