Effect of V₂O₅ addition on the structural and magnetic properties of Ni–Co–Zn ferrites

The effect of V₂O₅ addition on the structural and magnetic properties of Ni–Co–Zn ferrites having the compositions Ni_0.62Co_0.03Zn_0.35Fe₂O₄ + xV₂O₅ (where x = 0.0, 0.5, 1.0 and 1.5 wt%) are reported. The samples were prepared by solid state reaction. 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 and coercivity were determined from the magnetic hysteresis loops, while Curie temperatures were estimated from the temperature dependence of magnetization. The saturation magnetization almost linearly decreased from 77 emu g⁻¹ for x = 0.0 wt% V₂O₅ to 56 emu g⁻¹ for x = 1.5 wt% V₂O₅. Curie temperatures for the studied samples decreased with increase of V₂O₅ addition. A general termed of permeability enhancement is clearly evidenced on V₂O₅ addition. (paper)