Magnetoelectric response in lead-free Na0.4K0.1Bi0.5TiO3/NiFe2O4 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 (epsilon')similar to 1450 at 1 kHz, remanent polarization (P-r)similar to 39 mu C/cm(2), coercive electric field (E-c)similar to 27 kV/cm and maximum strain (S-max)similar to 0.3 % of NKBT along with saturation magnetization (M-s)-49 emu/g, coercive magnetic field (H-c)similar to 27 Oe and magnetostriction (lambda)similar to-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 H-dc similar to 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.

Automated summary

Lead-free NKBT and NFO ceramics were synthesized and laminated NKBT/NFO composites were prepared. The composites showed a high ME response, making them suitable for sensor and energy harvesting applications.