Impact of cobalt substitution on cation distribution and elastic properties of Ni-Zn ferrite investigated by X-ray diffraction, infrared spectroscopy, and Mo center dot ssbauer spectral analysis

The present study deals with site occupancy of cobalt in Ni-Zn ferrite investigated by in-field Mo center dot ssbauer spectroscopy at 300 K, 77 K, and 5 K coupled with X-ray diffraction, Fourier transform infrared spectroscopy, and Rietveld analysis. The cation distribution for the whole series of compositions was proposed by consideration of the amounts of iron ions present at tetrahedral and octahedral interstitial sites. Confirmation of the proposed distributions was achieved by quantitative estimation of the lattice constants for these compositions and comparison with experimental values. Pauling electronegativities remain almost constant, indicating no significant variation in the strength of the ionic bond with cobalt substitution. The observed decrease in the Debye temperature calculated with both the Waldron formula and the Anderson formula suggests that as a result of cobalt doping, there is slight enhancement in lattice vibrations, which is attributed to the minor weakening of the interatomic bonding between the atoms in the spinel lattice.

Automated summary

The present study investigated the site occupancy of cobalt in Ni-Zn ferrite using various analytical techniques and proposed a hypothesis about cation distribution. Experimental results showed that there was a slight enhancement in lattice vibrations with cobalt doping, and no significant variation in the strength of the ionic bond.