Magnetic characteristics of zinc substituted cobalt ferrites

Abstract

A series of Co1-xZnxFe2O4 ferrite(x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5) compositions were synthesized using the standard double sintering ceramic technique, sintered at 1050°C for 2 hours. Substituting Zn in place of Co influenced the structural, dielectric and magnetic properties of CoFe2O4samples. Structural analyses were carried out using X-ray diffraction (XRD). The XRay

diffraction pattern confirmed the single-phase cubic spinel structure and the sharp peak revealed that the samples are in good crystalline form. The lattice parameters were calculated for each composition and found to increase with Zn substitution. A significant increase in density and subsequent decrease in porosity were observed with increasing Zn content. The grain size of the samples was reduced by enhancing the Zn concentration. The dielectric constant (ε′) of the sample is found to decrease with increase in frequency exhibiting normal dielectric behavior. Dielectric relaxation peaks were observed for the frequency dependence of dielectric loss tangent curves. The observed dielectric properties were explained on the basis of electron conduction mechanism. The variation of the resistivity versus temperature was also studied and the dielectric constant of the system has a variation quite similar to that of the resistivity. Vibrating Sample Magnetometer measurement confirmed that the magnetizations of all the samples were saturated. Saturation magnetization and coercivity were estimated with variation of Zn content. These effects are due to facilitation of demagnetization by substitution of the non-magnetic Zn ions. Permeability was found to decrease with increase in Zn content. Cobalt Ferrites have the characteristics of electromagnetism, excellent chemical stability, mechanical hardness, low coercivity, moderate saturation magnetization and high anisotropy constant. Hence, Zinc substituted Cobalt Ferrite is a good candidate for synthesizing as dielectric, magnetic, multiferroic material and also for using in storage devices in advancement of science and technology.