Abstract: Nanocrystalline γ′-Fe_{4^{Nthin films were synthesized on single crystal Si (100) substrate by facing target magnetron sputtering. The structure and magnetic properties at room temperature and low temperatures were characterized by means of X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The results indicate that the film had a single easy magnetized direction along (111). In a temperature range of 80~350 K, the saturation magnetization σs and coercive force Hc increased, whereas the ratio σr/σsdecreased with decreasing measured temperature. The relation between the coercive force Hc and temperature T obeyed the T1/2 law, the relation between σs and T did not obey the Bloch T3/2 law, which means that the interaction among spin waves should be considered. }}

Key words: nanocrystalline γ′-Fe₄N thin film, structure, low temperature, magnetic properties