Structural and Magnetoelectrical Properties of MFeO (M = Co, Ni, Cu, Mg, and Zn) Ferrospinels Synthesized via an Egg-White Biotemplate.

Nanocrystalline metal ferrites (MFeO, M = Co, Ni, Cu, Mg, and Zn) were successfully synthesized via autocombustion synthesis using egg white. X-ray diffraction (XRD) measurements revealed the crystallization of the entire ferrites either in the tetragonal structure, such as in the case of CuFeO, or cubic spinels such as in other studied ferrites. The Fourier transform infrared spectral study revealed the characteristic vibration bands of ferrites. Compared to other synthesis methods, the observed variation in the obtained structural parameters could be due to the different cation distribution of the prepared ferrites. In agreement with XRD measurements, the transmission electron microscopy images showed agglomerated particles with cubic morphology for all ferrites. On the other hand, CuFeO showed tetragonal morphology. The magnetization values were found to vary with the type of the metal ion, and CoFeO showed the highest one (42.8 emu/g). Generally, the lower magnetization values obtained than those reported in the literature for all studied ferrites could be attributed to the smaller particle sizes or the cation redistribution. The obtained coercivity values are observed to be higher than their related values in the literature, exhibiting the impact of the present synthesis route. Ac-conductivity as a function of temperature and frequency indicated semiconducting properties with the observed change in the conduction mechanism by increasing the temperature. The obtained low dielectric constant values could suggest using the entire ferrites in high-frequency applications such as microwave devices.