A study of structural, ferroelectric, ferromagnetic, dielectric properties of NiFe2O4–BaTiO3 multiferroic composites

The mixed spinel-perovskite multiferroic composites of xNiFe2O4-(1 − x)BaTiO3 (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) have been prepared by sol–gel method. The structure and morphology of the composites were examined by means of X-ray diffraction and transmission electron microscope. High-resolution transmission electron microscope image indicates a clear view of ferrite and ferroelectric phase. Moreover, we observed a fine interface between the two phases, where the coupling effect of ferrite and ferroelectric phase happened. The composites show excellent ferromagnetic and ferroelectric properties. The saturation magnetization (Ms) reaches to 24.139 emu/g for x = 0.6 at room temperature, the magnetization is about 2.37 emu/g for x = 0.6 when the temperature decreases to 90 k, and the polarization reaches to 3.75 μC/cm2 for x = 0.1. Frequency dependent variations of dielectric constant and loss tangent for xNiFe2O4-(1 − x)BaTiO3 were studied in detail.