Enhanced DC electrical resistivity and magnetic properties of transition metal cobalt substituted spinel MgFe2O4 ferrite system

Abstract

Cobalt-substituted magnesium ferrite materials, denoted as Mg1-xCoxFe2O4 (with × = 0.0, 0.25, 0.5, and 0.75), were synthesized using the solid-state reaction method at 1200 °C. This study aimed to investigate these ferrite systems' morphology, structure, DC electrical resistivity, and magnetic characteristics. Various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), Fourier-transform infrared (FT-IR) spectroscopy, DC electrical resistivity measurements, and vibrating sample magnetometer (VSM), were employed to assess the phase purity, microstructure, elemental composition, functional groups, resistivity, activation energy, and magnetic properties of the ferrite particles. The XRD patterns revealed a spinel cubic structure with the Fd3m space group. SEM images exhibited a few agglomerations and grains with spherical and polyhedral shapes, measuring 1.5 to 2 µm. The FTIR spectrum displayed two wavebands (ν1 and ν2) in the range of 400 cm−1 to 600 cm−1, corresponding to the lattice's tetrahedral and octahedral sites. Activation energies, which increased with higher cobalt concentrations, were calculated from DC electrical resistivity measurements. Furthermore, saturation magnetization and coercivity values gradually increased with rising cobalt concentrations.