Magnetic Properties of Iron Nitride Thin Films Prepared by the Magnetron Discharge Method

The saturation magnetization Ms of polycrystalline iron thin films increased by approximately 10% after films were subjected to ion nitriding treatment for about one hour. In the latter treatment, the magnetron discharge method was used to increase the energy density of the discharge. The rate of increase of Ms was 21.2% after the iron thin film was nitrided under an N2 gas pressure of 4.5×10^¿2 Torr. X-ray diffraction studies revealed the presence of Fe16N2, ¿¿-Fe4N, ¿-Fe3N, ¿-Fe2N, and ¿-Fe phases in thin films nitrided under various N2 gas pressures. The saturation magnetization Ms of Fe16N2, calculated using X-ray integrated intensity ratios, was 2210 emu/cc in nitrided thin films under an N2 gas pressure of 4.5×10^¿2 Torr, and the Ms of Fe16N2, calculated using X-ray integrated intensity ratios, was 1710 emu/cc for thin film nitrided under an N2 gas pressure of 7.5×10^¿2 Torr.