Effect of Pentavalent Vanadium Ion Doping on Magnetic Properties of Nickel Ferrite Determined Via 57fe IFNMR and FMR Studies

We have synthesized a series of vanadium-doped nickel ferrite samples to investigate the impact of this substitution on the material's magnetic properties. The samples' phase purity has been verified by XRD analysis. Micrographs taken with a SEM instrument show the accelerated development of the grains. All of the samples are ferrimagnetic, as shown by Vibrating Sample Magnetometry (VSM), but the saturation magnetization (MS) decreases up to (x = 0.20), after which it increases. The samples are also studied by FMR and using the enhanced simulation conditions, the magnetocrystalline anisotropy constant (K-1) of nickel ferrite is calculated, and it is found to be in excellent agreement with the previous reports. The effect of anisotropy on the strength of the signal is investigated using Fe-57-IFNMR (echo amplitude). Intriguingly, we have found that the magnetocrystalline anisotropy measured by FMR is inversely correlated with the echo amplitude measured by IFNMR.