Enhanced magnetic performance in exchange-coupled CoFe₂O₄-LaFeO₃nanocomposites

Nanocomposite oxide system of (x)CoFe₂O₄-(100-x)LaFeO₃with different weight percent of core-shell structured CoFe₂O₄(x = 0, 20, 40, 50, 80, 100) and LaFeO₃were fabricated, via a two-step sol-gel wet-chemical synthesis technique. The phase formation of the composites was confirmed by x-ray diffraction and the structural parameters of both the phases were attained from the Rietveld refinement results of XRD patterns. The elemental composition and microstructure of the resulting nanocomposites were examined by using energy-dispersive x-ray spectroscopy and high-resolution transmission electron microscopy technique, respectively. The detailed magnetometry studies at 300 K and 5 K reveal that the inter-and intra-phase magnetic interactions affect the saturation magnetization (M_S), remanence magnetization (M_R) and coercivity (H_C) values of this bi-magnetic system. The remarkable feature of 'pinched magnetic hysteresis loop' was evidenced in the [(50) CoFe₂O₄- (50)LaFeO₃] composite, leading to a lesser magnetic loss factor and better magnetic performance of this sample. The report depicts an improved interfacial exchange coupling at 5 K, for the nanocomposites of core-shell morphology and offers an understanding or explanation of improved magnetic performance for the (50)CoFe₂O₄- (50)LaFeO₃nanocomposite and opens up an important way to design new multiferroic applications in low magnetic fields.