Investigation of the Structural, Magnetic and Transport Properties of Yttrium Substituted Ni-Zn Ferrites

Abstract

The present research work is focused on Yttrium (Y) doped Ni-Zn ferrites. The ferrite samples of the composition Ni0.25Zn0.75YxFe2-xO4 [where x= 0.00, 0.02, 0.04, 0.06 and 0.08] were synthesized by conventional solid state reaction method. As a part of synthesis the samples were pre-sintered at 850°C for 2 hours and sintered at 1150°C for 3 hours. The effect of rare earth Y3+ substitution on the structural, magnetic and electrical properties of the Ni-Zn ferrites was studied. The phase identification and lattice parameter determination were carried out by using X-ray diffraction (XRD). XRD patterns show that all the samples consisted of the single phase cubic spinel structure with an extra peak in x=0.08. The lattice parameters gradually increases with increasing Y content but it slightly decreased for x=0.08. The bulk density suddenly decrease for x=0.02 then increases with increasing rare earth Y3+ ion and again slightly decreased for x=0.08. The X-ray density increases continuously with increasing x-content. The microstructural analysis was done by Scanning Electron Microscopy (SEM). The SEM images show that the samples exhibit uniform surface morphology with well-defined spherical grains. The average grain size was calculated using Image J software and it can be observed that the average grain size gradually increased with Y content except x=0.08 where it decreases suddenly. The complex permeability, loss tangent and dielectric properties were investigated as a function of frequency range 1 KHz to 120 MHz by using an impedance analyzer. The initial permeability was found in steady state to a higher order of frequency range from 103 Hz - 50 MHz. Continuous decrease of the dielectric constant with the increasing frequency and remains almost constant at higher frequency range has been observed. The magnetic properties have been studied by Vibrating Sample Magnetometer (VSM). The saturation magnetization(Ms), coercivity(Hc), remanent magnetization(Mr) and the ratio of remanent magnetization and saturation magnetization have been calculated from the M-H loop at room temperature. The values of Ms were decreases with increasing Y3+ content. Moreover, coercivity decreases with increasing Y content. Doping of Y ion lowers the conduction and subsequently an increase in resistivity is observed. The characteristics of electromagnetism, excellent chemical stability, mechanical hardness, high coercivity, and moderate saturation magnetization have made Y doped Ni-Zn ferrite a good candidate for synthesizing and investigation to contribute in science and technology.