Effectof V2O5 additionon the structural, magnetic and electrical properties of Ni-Co-Zn ferrites

Abstract

The effect of V2O5 addition on the structural, magnetic and electrical properties of Ni-Co-Zn ferrites having the compositions Ni0.62Co0.03Zn0.35Fe2O4 + xV2O5 (where x= 0.0, 0.5, 1.0 and 1.5wt%) are reported. The samples were prepared by solid state reaction and sintered at 1200oC. The crystalline structure of all the samples showed cubic spinel structure. The microstructural study reveals that the grain growths of Ni-Co-Zn mixed ferrites are strongly depended on the amount of V2O5 contents. The saturation magnetization (MS) and coercivity (HC) were determined from the magnetic hysteresis loops, while Curie temperatures (TC) were estimated from the temperature dependence of magnetization. The MS almost linearly decreased from 77emu/g for x= 0.0 wt% V2O5 to 56.5 emu/g for x= 1.5wt% V2O5. Similarly, TC for the studied samples gradually decreased with increase of V2O5 addition upto x=1.0 wt% V2O5 and displayed an upturn at x= 1.5 wt% V2O5. A general termed of permeability enhancement is clearly evidenced on V2O5 addition. The dielectric constant and dielectric loss factor were measured for all the samples as a function of frequency at room temperature. The variation of ac resistivity with applied frequency was also measured at room temperature. The ac resistivity decreases with increasing of frequency and then it remains constant at higher frequency for all the compositions.