Synthesis and Investigation of Electrical and Magnetic Properties of Co-Ni Substituted Spinel Ferrites Nanoparticles

Abstract

The nanocomposite of spinel ferrites and multi walled carbon nanotubes (MWCNTs) is synthesized and structural, electrical, and magnetic properties were investigated. Zinc and Nickel substituted Cobalt ferrites were prepared using the simple and economical method of nanoparticles synthesis called Co-precipitation. A nanocomposite is achieved by coating MWCNTs with ferrites using toluene as a dispersive medium. Different loadings of the MWCNTs have been applied to see the effect of MWCNTs on the magnetic and dielectric properties. The loadings applied were 0%, 0.25%, 0.50%, 0.75% and 1%. The prepared nanocomposites were structurally characterized using X-ray diffraction and Fourier transform infrared spectroscopy. The obtained XRD patterns verified the formation of pure Face Centered Cubic single phase of Zn0.2Ni0.3Co0.5Fe2O4/MWCNTs nanocomposite. The average crystallite size for the zinc and nickel substituted cobalt ferrites measured by Debye-Scherrer equation was 15 nm ± 3 nm. The average crystallite size for each sample was in complete agreement with the results obtained from high resolution scanning electron microscope within experimental error. Scanning electron microscope results showed aggregation of ferrite nanoparticles on MWCNTs. The dielectric properties were analyzed and enhanced via the addition of MWCNTs. The dielectric constant of pure Zinc and Nickel substituted Cobalt ferrites was 1×105 whereas it was increased with the addition of MWCNTs. At wt. 1% MWCNTs, the dielectric constant was increased to 3.75×108 at frequency of 100 Hz. The A.C conductivity is maximum at lower frequency which represents the dominance of band conductivity over hopping conductivity. DC electrical conductivity of nanocomposites were also measured and is observed to increase with the increase in loading percentage of MWCNTs proving the conductive behavior of MWCNTs. VSM analyses the magnetization saturation of nanoparticles which turns out to be 63.7 emu/g for Zn0.2Ni0.3Co0.5Fe2O4 nanoparticles and 35.1 emu/g for Zn0.2Ni0.3Co0.5Fe2O4/1% wt. MWCNTs nanocomposite.