Tailoring the properties of Ni-Zn-Co ferrites by Gd3+ substitution

Structural, magnetic and electrical properties of Ni0.7Zn0.2Co0.1Fe2-xGdxO4 (x = 0.00, 0.02, 0.05, 0.07, 0.1 and 0.12) ferrites, prepared by the standard solid-state reaction technique have been studied. The single phase of cubic spinel structure was confirmed by X-ray diffraction. The lattice constant, bulk density and porosity were calculated. The FE-SEM examined the surface morphology of the prepared samples. Real and imaginary parts of the complex permeability and magnetic properties of the samples were measured using Impedance Analyzer and VSM respectively. Initial permeability decreases with increasing of Gd content up to x = 0.05 and then increases with Gd. The dielectric constant and dielectric loss tangent of the studied samples decreased with the increase of Gd concentration. The eddy current loss of the prepared samples is expected to decrease with the increase of Gd content due to increase in ac resistivity. Complex impedance plots were studied to understand the contribution of grains and grain boundary resistances.