Dielectric and magnetoelectric properties of (BiBa)(FeTiZn) O3/CoFe2O4 lead-free particulate composites

Abstract The magnetic, dielectric, and magnetoelectric (ME) properties of particulate composites containing lead-free piezoelectric 0.97[0.67BiFeO3-0.33BaTiO3]-0.03Bi(Zn0.5Ti0.5) O3 (BF33BT-3BZT) and magnetostrictive CoFe2O4 (CFO); (100-x)[BF33BT-3BZT]-xCFO, x = 13, 25, 37, 47 mol%; have been investigated. The pure ferroelectric BF33BT-3BZT shows a non-dispersive and sharp phase transition, while the composites exhibit relaxor behavior which is described by Vogel - Fulcher law. The ME voltage coefficient is studied as a complex quantity and its dependence on magnetic field is discussed within the framework of dynamic magnetostriction. The composite with x = 37 shows the highest ME voltage coefficient of 5.7 mV/cm.Oe. The results show that, compared to cobalt ferrite, the composite of BF33BT-3BZT with nickel ferrite produces larger ME voltage at a lower magnetic field, confirming that the magnetic field dependence of magnetostriction has a crucial role on the ME properties of the studied multiferroic composites.