Design, Preparation, and Magnetic Properties of Fe4N/Fe3N Soft Magnetic Composites Fabricated by Gas Nitridation

Fe4N/Fe3N soft magnetic composites (SMCs) prepared by gas nitriding were studied. In this paper, Fe4N was obtained by nitriding pure iron in NH3/H-2, then nitrided by pure ammonia gas to obtain Fe4N/Fe3N SMCs. The morphology, structure, and magnetic properties were studied by SEM, VSM, B-H Tester, and Impedance Analyzer. With the increase of nitridation time, Fe3N content gradually increased and reached saturation after nitriding for 5 h, saturation magnetization M-S decreased, and M-s was equal to 178.4 emu/g when nitriding time reached 8 h. With the increase in frequency, the effective permeability of Fe4N/Fe3N SMCs decreases, and the core loss increases. The synthesis of Fe3N generally reduced the effective permeability and loss of Fe3N/Fe4N SMCs, except for the 8 h nitrided sample. With the increase in frequency, complex permeability also decreased and tended to be stable. 8 h nitrided SMC has the largest Q and mu '.