Amorphous Fe–B–N films deposited by reactive sputtering of a FeB target

Fe–B–N films are deposited on glass and silicon substrates by DC magnetron sputtering of a FeB target in Ar–N2 reactive mixtures. The nitrogen concentration in the films is controlled by the flow rate of nitrogen introduced in the deposition chamber. The films are characterised by X-ray diffraction, X-ray photoemission spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). All films prepared by the above method are amorphous, irrespective of the nitrogen flow rate. FTIR and XPS analyses evidence boron–nitrogen bonds in the Fe–B–N films. Furthermore, XPS analysis shows that the number of these bonds increases with the nitrogen flow rate, while the number of boron–iron bonds decreases. Thus, the chemical environment of boron atoms appears to be strongly dependent upon the nitrogen flow rate. Finally, the electrical resistivity and the free corrosion potential of Fe–B–N films are measured as a function of the nitrogen flow rate.