Hydrothermal growth and characterization of magnetite (Fe3O4) thin films

Well-crystallized magnetite (Fe3O4) thin films were successfully prepared by a simple hydrothermal process using hydrazine hydrate as the mineralizer. X-ray diffraction and scanning electron microscopy (SEM) and transmission electron microscopy were employed to characterize the products. SEM images show that the uniform Fe3O4 film (∼ 3 μm in thickness) is firmly grown on a nickel substrate. The magnetic property of the Fe3O4 particles scraped from the film was measured by Physical Property Measurement System (PPMS) at room temperature, and the magnetization curve reveals a soft ferromagnetic behavior with high saturation magnetization of 85 emu/g. Furthermore, the chemical and growth mechanisms for the hydrothermal formation of the Fe3O4 film are discussed.