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 similar to 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. (C) 2009 Elsevier B.V. All rights reserved.