Structural, microstructural and multiferroic properties of BiFeO₃–CoFe₂O₄ composites

BiFeO₃–CoFe₂O₄ composites were successfully prepared via conventional solid state method. Powder X-ray diffraction confirmed the presence of both perovskite BiFeO₃ (BFO) and spinel CoFe₂O₄ (CFO) phases and rhombohedral structure due to splitting in major peaks in the composites. Further insight into the microstructural and morphological properties of the composites was provided by Raman spectra, Fourier Transform Infrared Spectroscopy and Field Emission Scanning Electron Microscopy along with EDX analysis. Magnetic and electrical response of the composites has been studied exhaustively to comprehend their multiferroic properties. Magnetization study (magnetization vs. magnetic field) confirmed the high saturation magnetization in composites with a low value of coercivity at room temperature. The maximum saturation magnetization (0.3902 emu/g) was achieved in BFO–30%CFO. Ferroelectric polarization (polarization vs. electric field) loop measurements confirmed the low electrical leakage current in the composites. The temperature dependent dielectric response of the composites suggested existence of magnetoelectric coupling between the ferroelectric and ferromagnetic orders in the vicinity of antiferromagnetic–paramagnetic transition temperature of BFO. The decrease in dielectric loss with an increase in CFO content in the composites also validated the similar results as observed in polarization versus electric field measurements. The Impedance Spectroscopy at room temperature revealed the non-Debye behavior and high resistivity of the composites.