Preparation and magnetic properties of iron titanium oxide nanotube arrays

FeTi alloy was prepared by a vacuum smelting method, iron titanium oxide nanotube arrays have been made directly by anodization of the FeTi alloy. Morphologies and microstructures of the samples were characterized by scanning electron microscope, transmission electron microscope, and X-ray diffractometer. Influences of temperature and H2O concentration on the morphologies of the nanotube arrays have been discussed in detail. Magnetic properties of the samples have also been investigated. The as-prepared samples were amorphous. When annealed at 500 °C and 550 °C, pesudobrookite Fe2TiO5 was obtained. At 600 °C, there were mixed Fe2TiO5, rutile TiO2, and α-Fe2O3. Magnetic performance of the nanotube arrays exhibited high sensitivity to temperature and changed interestingly upon annealing. The values of the coercivity and remanence were 340 Oe and 0.061 emu/g respectively for the sample annealed at 550 °C.