Microstructure and magnetic properties of nanostructured NiZnCu ferrite powders synthesized by sol-gel process

Nanostructured spinel NiZnCu ferrites were prepared by the sol-gel method from metal nitrate raw materials. Analyses by X-ray diffraction and scanning electron microscopy showed the average particle size of NiZnCu ferrite was under 50 nm. The single phase of NiZnCu ferrites was obtained by firing at 250(degree)C, resulting in nanoparticles exhibiting normal ferrimagnetic behavior. The nanotructured Ni/sub 0.2/Zn/sub 0.8-x/Cu/sub x/Fe/sub 2/O/sub 4/ (x=0.2~0.6) were found to have the cubic spinel structure. NiZn ferrite phase substituted by Cu was obtained before using the additive but hematite phase partially appeared at x=0.6. On the other hand, the hematite phase in this NiZnCu ferrite disappeared after using the additive of acetyl acetone small amount. The saturation magnetization M/sub S/ of Ni/sub 0.2/Zn/sub 0.8-x/Cu/sub x/Fe/sub 2/O/sub 4/ in this work as measured was about 51 emu/g at 77 K and 19 emu/g at room temperature, respectively.