Dielectric, magnetic, and structural investigation of Cr substituted cobalt nanoferrite via auto-combustion

Ferrite with the formula CoCrxFe2−xO4 (x = 0.05, 0.10, 0.15, and 0.20) (CCF) prepared by sol–gel process were studied. The structural, morphological, magnetic properties, and di-electric behavior of the specimens were understood by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Energy-dispersive X-ray (EDX) spectroscopy, Field electron scanning microscopy (FE-SEM), vibrating sample magnetometer (VSM), and impedance analyzer. The lattice parameter declines from 8.383 to 8.342 Å. The substitution of the larger Fe3+ ion (0.73 Å) by the smaller Cr3+ ionic radious (0.68 Å). In SEM the porosity in ferrite powders may have developed as a result of the fabrication that emits gases. The results of the FE-SEM picture indicate some agglomerated spherical and polyhedral form architecture with modest grain sizes in the range of (65.30–90.22 nm).The produced nanoferrite powders change from hard magnetic materials to soft magnetic ones when the magnetic characteristics are improved and hysteresis loop get narrowers. Hc drops off from 991 to 396 Oe, due to deformity in the samples. At room temperature, the impedance analyzer was used to study the dielectric factors such as the dielectric constant, dielectric loss, and ac conductivity for all specimens in terms of frequency. It is evident from plots of the dielectric constant (εʹ) and tan (δ) vs ln (f) that εʹ and tan δ decreases at low frequency from 102 to 104 Hz areas explained by Maxwell–Wagner interfacial polarization and remains steady at high frequency values. The results of this study are critically significant and will have a significant impact on future developments in magnetic recording equipment.