Evidence of magneto-electric coupling and electrical study of CFO modified BNT/BT composites

(1-x)(0.93Bi0.5Na0.5TiO3 /0.07BaTiO3 )-xCoFe2O4 ((1-x)BNT/BT-xCFO, where x = 0.1, 0.2, 0.3, 0.4 and 0.5) composite samples were synthesized by microwave assisted solid state reaction route and sintered at 1050 °C. X-ray diffraction study showed the presence of ferroelectric/ferromagnetic (FE/FM) phases without any peak of secondary phase. This was further confirmed by SEM study showing the presence of both FE/FM grains distinctly. Frequency dependent dielectric study showed maximum dielectric constant (εr) for the composite sample with x = 0.4. Polarization versus electric field (P-E) loop study revealed that maximum remnant polarization (2Pr = 1.75 µC/cm2 ) was found also for the 0.6BNT/BT-0.4CFO sample. Remnant magnetization (Mr) of the composite sample with x = 0.4 was found to be ∼7.81 emu/g. Magnetodielectric (MD) study of the 0.6BNT/BT-0.4CFO composite sample showed decrease in εr with the application of magnetic field and a MD effect of ∼2.4% (at 10 kHz) was found. Low leakage current value (∼10−4 A) was obtained in the 0.6BNT/BT0.4CFO composite sample. Change in piezoresponse force microscopy contrast after poling indicated on the changes in polarization of the ferroelectric domains. Reduction in Mr , observed in magnetic force microscopy contrast gave a clear evidence of presence of electric field induced magneto-electric (ME) coupling in the 0.6BNT/BT-0.4CFO composite sample.