Effects of annealing atmospheres on the structure and ferromagnetic properties of Fe0.12Cu0.02Zn0.86O thin films

Fe0.12Cu0.02Zn0.86O thin film was deposited on a Si substrate using r. f. sputtering with no heating and an Ar/O2 ratio of 10%. After deposition, the specimens were annealed at 400 °C for 1 h, in nitrogen and hydrogen atmospheres. The X-ray diffractometry (XRD) analysis results show that the crystallinity of Fe0.12Cu0.02Zn0.86O thin film annealed in a nitrogen atmosphere is better than that of the film annealed in a hydrogen atmosphere. The X-ray photoelectron spectroscope (XPS) results show that there are more oxygen vacancies in the Fe0.12Cu0.02Zn0.86O thin film annealed in a hydrogen atmosphere. The magnetic force microscope (MFM) analysis results also demonstrate that some magnetism particles are precipitated for the Fe0.12Cu0.02Zn0.86O thin film annealed in a hydrogen atmosphere. This results in an improvement in the ferromagnetic properties, and the saturation magnetization is 70.2 emu/cm3, which is about 25% larger than that for the as-grown Fe0.12Cu0.02Zn0.86O thin film.