Structure and magnetic properties of Ni _x Zn_1−x Fe₂O₄ thin films prepared through electrodeposition method

Nanocrystalline nickel–zinc ferrites Ni _x Zn_1−x Fe₂O₄ thin films have been studied and synthesized via electrodeposition–anodization process. Electrodeposited (NiZn)Fe₂ alloys were obtained from non-aqueous ethylene glycol sulphate bath. The formed alloys were electrochemically oxidized (anodized) in aqueous (1 M KOH) solution, at room temperature, to the corresponding hydroxides. The parameters controlling the current efficiency of the electrodeposition of (NiZn)Fe₂ alloys such as the bath composition and the current density were studied and optimized. The anodized (NiZn)Fe₂ alloy films were annealed in air at different temperatures ranging from 850 to 1000 °C for different times from 1 to 4 h. The change in the crystal structure, crystallite size, microstructure, and magnetic properties of the produced ferrites were investigated using X-ray diffraction patterns (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The results revealed the formation of Ni–Zn ferrites thin films were formed. The crystallite sizes of the produced films were in the range between 32 and 81 nm. High saturation magnetization of 48.81 emu/g was achieved for Ni_0.5Zn_0.5Fe₂O₄ thin film produced after annealing the alloy at 850 °C for 4 h. The annealing process of the oxidized alloy anodization process was found to be first order reaction. The activation energy of the crystallization of Ni–Zn ferrite was found to be 62 KJ/mol.