Fine Fe16N2 powder prepared by low-temperature nitridation

Abstract α-Fe was prepared by reduction of a fine γ-Fe2O3 powder under hydrogen at 500 °C for 8 h. The α-Fe fine powder, about 100 nm in crystallite size, was then nitrided under an ammonia flow at 130 °C for 100 h. X-ray single-phase Fe16N2 was obtained with a magnetization value of 225 emu/g at room temperature under a magnetic field of 15 kOe. The Mossbauer spectrum at room temperature could be resolved into three sets of hyperfine fields with an average magnetic moment of 2.52 μB. An additional paramagnetic component was present in the spectrum with an area ratio of 19%.