Controlled magnetic properties by tuning TbCu7 /Th2Zn17 phase in isotropic Sm-Fe-Nb-N compounds

Hard magnetic Sm1+xFe9.5Nb0.1Nδ (x = 0, 0.05, 0.10, 0.15) powders were synthesized by melt-spinning, annealing and nitriding. The structure and magnetic properties have been investigated by means of powder X-ray diffraction, vibrating sample magnetometer and high-resolution transmission electron microscopy. By changing the Sm content and correspondingly adjusting the ratio of TbCu7-type structure and Th2Zn17-type structure, the magnetic properties can be tuned accordingly and a series of high performance Sm-Fe-N magnetic powders can be obtained. The maximum energy product obtained was 15.50 MGOe associated with the intrinsic coercivity of 9.10 kOe for the SmFe9.5Nb0.1Nδ, and 13.50 MGOe associated with the highest coercivity of 13.30 kOe for the Sm1.1Fe9.5Nb0.1Nδ, which can be used as the potential isotropic magnetic powders in the bonded magnets.