Investigation of Cr Doped MG Ferrites (Paperback)

The polycrystalline samples of MgCrxFe2-xO4 ferrites were prepared by the conventional solid state ceramic sintering technique in air. The x-ray diffraction patterns obtained showed sharp peaks indicating the formation of single phase cubic spinel structure. Magnetic measurements were performed in order to investigate different magnetic properties of the samples. The Curie temperature (Tc) for all the samples has been determined where the Hopkinson type of effect at Tc has been observed with the manifestation of a sharp fall in permeability. The electrical resistivity measurements have been carried out as a function of temperature. The activation energies were found to be decrease with increasing Cr content. The lower activation energies are associated with higher electrical conductivity. The AC resistivity and dielectric constant of the samples are found to decrease with increasing frequency, exhibiting normal ferromagnetic behavior. The observed variation of electrical and dielectric properties of MgCrxFe2-xO4 ferrites are explained on the basis of Fe2+/Fe3+ ionic concentration.