Structural, morphological and magnetic properties of divalent copper-substituted Co-Zn Nanoferrites

Nanocrystalline Co0.5-xZn0.5CuxFe2O4 spinel ferrites were prepared by autocombustion method with citric acid as fuel. Paramagnetic divalent copper ions substituted in place of ferromagnetic cobalt ions resulted in the modifications of structural and magnetic properties of the system. All samples were characterized with X-ray diffraction technique for structure determination. Crystallite sizes were calculated using Williamson-Hall plot and size-strain plots. Cation distribution and all other structural parameters were presented. Transmission electron microscopy measurements were done for x = 0 and x = 0.15 and they showed well-developed spherical particles with average sizes of 35 nm and 48 nm. Morphological studies were performed and grain growth was observed to be increased with copper concentration. EDAX measurements revealed the stoichiometric proportions of the samples as per the chemical composition. Mid-IR spectroscopy was used to characterize the spinel phase and displayed two characteristic absorption bands in all samples with a slight shift. M-H loops were recorded using vibrating sample magnetometer at room-temperature and highest saturation magnetization was observed to be 50.2 emu/g for the base (x = 0) sample. Magnetocrystalline anisotropy was discussed with the help of magnetocrystalline anisotropy constant K-1.