The Preparation And Characterization Of Iron Oxide, Iron Nitrogen Oxide Thin Films

Recently, with the progress of science and technology, Fe-O and Fe-N thin films have been developed and applied to many fields because of their excellent properties. The Fe-O and Fe-N-O thin films were two-pole sputtered on different substrates. The thin films were treated with different temperature under air environment. The surface morphology, composition and structure character of the Fe-O and Fe-N-O thin films were studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The transmittance (T) and resistance of Fe-N-O films were studied by the UV755B ultraviolet-visible spectrometer and SZ82 four-point probe method. The results show that nitrogen in films has influence the optical property and structure of the Fe-N-O film. Before heat treatment, the main phases of Fe-N-O films were FeO and a little Fe16N2. The orientation of the deposited films was found by the results of TEM. The films were nanocrystalline, having crystal size of 50nm or less. But after heat treatment, the main phases were Fe2O3 and Fe3O4, having crystal size of 100nm or more, the orientation of the deposited films was disappeared. The results have proved the Fe-O and Fe-N-O films can absorb ultraviolet rays. The transmittance and resistance of the films have been increased when the heat treatment temperature increased. The reflectivity (R), absorption (A), the optical constants extinction coefficient (k) and the permeability ( r) were analyzed theoretically. The analytical results show that the R is a constant when the thickness of film is thicker. The films can also absorb all kinds of different wavelength rays. The results of corrosion test showed the films have the highest corrosion resistance against NaCl solution than any other iron materials. So it can be used to for along time under nature environment. But the films can also corrosion resistance against strong sour after heat treatment. The thickness of the films was measuredby the weight gain method. The thickness of the films was analyzed theoretically.We have proved that the thickness of the films depends on sputtering time,current, the films structure and binding.