Structural, dielectric and magnetic properties of Nickel-Chromium substituted Magnesium ferrites, Mg1xNixFe2-xCrxO4 (0 ≤ x ≤ 0.7)

In this paper, we report the structural, dielectric, and magnetic properties of Mg1-xNixFe2-xCrxO4 (0 <= x <= 0.7) ferrites synthesized via a solid-state process. The XRD patterns indicated forming a single-phase cubic spinel structure with a Fd-3 m space group for all samples with crystallite sizes ranging from 31.63 to 73.52 nm. Scanning Electron Microscopy (SEM) showed the formation of dense microstructure with an average grain size of 129.2 to 414 nm. The elemental analysis (EDS) confirmed the chemical purity for all the prepared samples. The saturation magnetization (M-s) was found to be maximum for the composition x = 0.3, after which it decreased due to the lower magnetic moment of Cr3+ ion (3 mu(B)) than that of Fe3+ ion (5 mu(B)). The samples' maximum magnetic saturation and coercivity are 62.04 emus/gm and 6.8 KOe, respectively. The measured sample's dielectric constant (epsilon') and loss tangent (tan delta) decreased with the increased applied field frequency, showing normal behavior. This can be explained in light of Maxwell-Wagner interfacial polarization and hopping of electrons between the Fe2+ <-> Fe3+ ions. Thus, the synthesized Ni-Cr substituted MgFe2O4 ferrite material is promising for recording materials.

Automated summary

In this paper, the structural, dielectric, and magnetic properties of Ni-Cr substituted MgFe2O4 ferrite material synthesized via a solid-state process were investigated. The results showed that the samples exhibited a single-phase cubic spinel structure with small crystallite sizes. The material had good magnetic saturation and coercivity, as well as a decreasing dielectric constant and loss tangent with increasing applied field frequency.