Structural, morphological, and magnetic study of low temperature synthesized Co0.75Ni0.25Fe1.95Dy0.05O4 nano ferrite

The nanoparticles of Co0.75Ni0.25Fe2-zDyzO4 (z = 0.0 and 0.05) were prepared by the sol-gel auto-combustion method. The cation distribution was calculated from the Rietveld refinement of the XRD pattern to confirm a mixed inverse spinel structure. The crystallite size was calculated by the Debye-Scherrer method, modified Scherrer method, Williamson Hall plot method, and size-strain plot method for prepared samples. The variation in crystallite size was observed due to the contribution of lattice strain on line peak broadening. From Fourier transform infrared (FT-IR) spectrum the absorption bands appeared at 574.79 cm(-1) and 414.70 cm(-1) reveals spinel ferrite structure for Co0.75Ni0.25Fe1.95Dy0.05O4. The particle size from a high-resolution scanning electron microscope (HR-SEM) the image was found to be 46.99 nm for Co0.75Ni0.25Fe1.95Dy0.05O4. Energy-dispersive X-ray spectrum (EDS) was confirmed the purity of the sample with good stoichiometry. The coercivity, retentivity, and saturation magnetization were estimated at 841.97 Oe, 30.95 emu g(-1) and 61.80 emu g(-1) respectively for Co0.75Ni0.25Fe1.95Dy0.05O4. The squareness ratio for Co0.75Ni0.25Fe1.95Dy0.05O4 nanoferrite was found to be 0.5 which is the ideal Stoner-Wohlfarth value. The experimental estimated net magnetic moment (n(B)) per formula was less than the theoretical value calculated from Neel's two sublattice model for prepared samples.