Enhanced ferromagnetic order in Mn doped BiFeO₃-Ni_0.5Zn_0.5Fe₂O₄ multiferroic composites

Multiferroic composites of 0.5 BiFeO₃-0.5Ni_0.5Zn_0.5Fe₂O₄ and 0.5Bi_0.95Mn_0.05FeO₃-0.5 Ni_0.5Zn_0.5Fe₂O₄ were prepared by combining sol-gel autocombustion and solid state methods. X-ray diffraction analysis of the composites reveals that the samples are formed as di-phase compounds while retaining the spinel phase for the Ni-Zn ferrite and perovskite phase for the Bi-ferrite. Fourier transform infrared spectroscopy measurements on the composites confirm their structures with the presence of Fe-O and Bi-O bonds. Dielectric measurements on the composites were used to discuss about the possible polarization/conduction mechanisms, phase transitions and magnetoelectric coupling. Room temperature ferroelectric and magnetic hysteresis loop studies on the samples ensure that the Mn doped composite exhibits enhanced remnant polarization as well as saturation magnetization compared to the undoped composite. Moreover, the Mn doping has further translated the composite into magnetically softened with coercivity almost close to zero. The obtained improvements in the dielectric and multiferroic properties of the composites are attributed to the corresponding structural modifications brought about by the Mn doping.