Magnetic Properties of Transition Metal Nitride--Synthesis of Iron Nitride by High-Dose Nitrogen Ion Implantation--

Nitrogen ions (N2⁺) were implanted into pure iron films in an attempt to produce Fe16N2 and other iron nitride phases. Ions were implanted at 150 keV and dosages were ranged from 2 × 10¹⁶ to 2.11 × 10¹⁷ ions/cm², and magnetization measurements and X-ray diffraction studies performed. Ferromagnetic Fe3N and Fe4N phases were found intermixed with the ¿-Fe, but there was no evidence of Fe16N2. The saturation magnetization decreased slowly with increasing dosage, but dropped abruptly by 40 percent at the highest dose, due to the formation of a paramagnetic Fe2N phase. This method is suggested as a means of improving iron surface properties without greatly degrading the magnetic properties.