Effect of composition on structural and magnetic properties of nanocrystalline ball milled Ni1−xZnxFe2O4 ferrite

Nanocrystalline Ni1−xZnxFe2O4 (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1) ferrite was produced by high energy ball milling of ZnO, NiO and Fe2O3 powder mixtures. X-ray powder diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM) were carried out to investigate structural, chemical and magnetic aspects of Ni–Zn ferrite. Ni1−xZnxFe2O4 appeared to form in two stages involving formation of Zn ferrite by faster diffusion of ZnO in Fe2O3 followed by diffusion of NiO in Zn ferrite to form Ni–Zn ferrite. The crystallite size of final product after 60 h of ball milling for all samples was found to be ∼18 nm independent of composition. It was found that the magnetization value of Ni1−xZnxFe2O4 initially increases and then decreases as Zn content increases with a maximum value of 83.2 emu/g at x=0.5. The coercivity value of Ni1−xZnxFe2O4 decreases steadily with increasing Zn content.