Characterization Of Coloured Films Of Fe-O-N Deposited By Reactive Magnetron Sputtering

Iron oxynitride films (FeNxOy) were deposited on different substrates by magnetron sputtering of an iron target in reactive Ar-N-2-O-2 mixtures. This study is focused on the effect of the partial pressure of oxygen on the physical and functional properties of FeNxOy coatings. The films' structure and the chemical composition of these films were determined by X-ray diffraction and Rutherford Backscattering Spectrometry, respectively. When increasing the oxygen flow rate, the films' structure evolved from a nitride one (epsilon-Fe2-3N) to an fcc one and finally to an oxide one (alpha-Fe2O3). Mechanical and electrical properties measured at room temperature were investigated during this research in connection to the oxygen flow rate. In addition, the colour variation of iron oxynitride films was measured in the CIE-L*a*b* system. The FeNxOy thin films with high oxygen content exhibited a reddish-brown colour. This colour and the different properties allow applications in decorative field to surface treatments for worn products.