EFFECT OF ZINC AND COPPER SUBSTIUTION ON STRUCTURAL, OPTICAL AND MAGNETIC PROPERTIES OF COBALT NANOFERRITES (CoFe2O4)

Abstract

In the present study, CoFe2O4 and Co.8Z0.1Cu0.1Fe2O4 ferrites were synthesized by sol-gel combustion method using oxalic acid as a chelating agent. The thermal, structural optical and the magnetic properties of these ferrites were investigated. For this investigation, thermogravimetric analysis (TGA), differential thermal analysis (DTA), x-ray powder diffraction (XRD), Ultraviolet visible (UV-vis) spectroscopy and electron spin resonance (ESR) spectroscopy characterization techniques were employed. The XRD analysis revealed the formation of a single phased cubic spinel ferrites. From XRD results, different structural parameters, such as lattice parameter, unite cell volume, crystal size, etc. of both ferrites were also suggested. The average crystallite sizes were found to be 40.673 and 43.3856 nm for CoFe2O4 and Co.8Z0.1Cu0.1Fe2O4 ferrites, respectively. This confirmed the nanocrystalline nature of all the synthesized ferrites. The optical band gap both ferrites were found to be 2.73ev and 2.76 eV for CoFe2O4 and Co.8Z0.1Cu0.1Fe2O4 ferrites, respectively. The value of Lande's g-factor, resonance field and peak to peak line width of both ferrites were determined from ESR spectroscopy study. From the g-factor values, it was suggested that the superexchange interaction in both ferrites arising from the cation redistribution in tetrahedral (A) and octahedral (B) sites.