Structural, magnetic, and dielectric properties of nanocrystalline Cr-substituted Co0.8Ni0.2Fe2O4 ferrite

The structural, magnetic, and electric properties of Co0.8Ni0.2CryFe2−yO4 (0.00≤y≤0.75; step 0.15) prepared via citrate precursor method are investigated. The structural properties of the produced nano-particles were examined through X-ray diffraction (XRD) and infrared spectroscopy (IR). The XRD pattern revealed a single phase cubic spinel structure for all the samples. The crystallite size decreases with increasing Cr content. Magnetic properties were recorded using vibrating sample magnetometer (VSM). The saturation magnetization increased first with y=0.15 then decreased continuously with further increase of Cr3+ content. Quite reasonable cation distribution was proposed for all the samples relying on the experimental results of lattice parameters, magnetization, and IR spectrum. Theoretically estimated lattice parameters and magnetic moments (using Neelʹs two sub-lattice model) obtained from the proposed cation distribution are in conformity with those experimentally obtained from XRD and VSM results, respectively. Chromium substitution was found to improve ac electric properties, which was revealed by analyzing frequency-dependent ac conductivity and loss factor.