The effect of synthesis parameter on crystal structure and magnetic properties of Ni_0.5Zn_0.5Fe₂O₄ magnetic nanoparticles

Nickel Zinc Ferrite (Ni_0.5Zn_0.5Fe₂O₄) magnetic nanoparticles have been successfully synthesized using the co-precipitation method with variation of synthesis temperature and concentration of NaOH. X-ray diffraction (XRD) analysis confirmed that Ni_0.5Zn_0.5Fe₂O₄ nanoparticles have spinel cubic crystal structure. The XRD profile of sample showed that the crystallinity increases with the increase of synthesis temperature. Meanwhile the XRD profile of sample showed the crystallinity decreases with the increase of NaOH concentration. Crystallite size of samples were in the range of 11.1-16.0 nm. There is no significant change in the lattice parameter size for the samples synthesized with increase of temperatures and NaOH concentrations. Transmission electron microscope (TEM) image showed that the sample was agglomerated. The selected area electron diffraction (SAED) image showed the diffraction ring as representation of Miller plane and confirmed that sample was polycrystalline. The maximum magnetization (σ_s ) at 15 kOe of the samples increases with the increase of crystallite size and crystallinity. The coercivity (H_c ) of the samples increases with the increase of crystallite size.