Existence of heterogeneous phases with significant improvement in electrical and magnetoelectric properties of BaFe12O19/BiFeO3 multiferroic ceramic composites

A series of (1-x)BaFe12O19-xBiFeO(3) (x = 0.0, 0.25, 0.50, 0.75 and 1.0) multiferroic ceramic composites have been synthesized using standard mechano-chemical activation technique. Room temperature magnetic hysteresis loop measurement indicates that the ferrimagnetic loop of the composites is strongly influenced by BaFe12O19 phase and therefore, a highly saturated magnetic characteristic has been observed in composites as compared to pure BiFeO3. Composites show a significant enhancement in ferroelectric properties, which may be attributed to the decrease in leakage current caused by the BiFeO3 addition. The variations of magnetic and magnetoelectric characteristics were analyzed with the help of various conduction mechanism occurring in these materials. An improved magnetoelectric coupling coefficient of up to 11.9 mV/(Oe.cm) was obtained for the sample with x = 0.50, which is nearly 1.5 times higher than the pure BiFeO3 ceramic. These results demonstrate that the substitution of BiFeO3 in an appropriate proportion can be a feasible way to improve the multiferroic properties of BaFe12O19.