Microstructure dependence of the magnetic properties of sintered Ni-Zn ferrites by solid-state reaction doped with V2O3

In order to improve the frequency range operation of Ni-Zn ferrites with the Ni0.7Zn0.3Fe2O4 stoichiometry in this study, they were doped with V2O3 at different concentrations (0, 0.25, 0.50, and 0.75 wt%). The samples were prepared by the solid-state reaction at 1250 degrees C for 24 h. The content and location of Vanadium in these ferrites allow us to determine its influence on their microstructure and magnetic properties. A single cubic spinel phase with lattice parameter variation was determined by the refinement of X-ray diffraction patterns. This refinement was achieved using the Rietveld method. The lattice parameter presents a slight enhancement with increasing Vanadium content up to 0.50 wt% of V2O3. The increase of intragrain porosity and the segregation of Vanadium at the grain boundary in samples with higher concentration of Vanadium show a narrow grain-size distribution that leads to a resonant character of the magnetic domain wall. A wide grain-size distribution determined in lower concentration of Vanadium results in a mixed resonant-relaxation dispersion. The use of V2O3 as a dopant in Ni-Zn ferrites increases the frequency operation and coercivity, H-c, without abruptly degrading the saturation magnetization, M-s. We, therefore conclude, that Vanadium may be used as a strong dopant for the preparation of ferrites for any particular high-frequency application.