Ce-substituted (Sm,Ce)2Fe17N3 compounds: A promising class of high-performance permanent magnets

In this work, the effects of partial substitution of Ce for Sm in (Sm1_ xCex)2Fe17N3 (x = 0.2-0.8) compounds on their intrinsic and extrinsic magnetic properties have been estimated. With the x progressively increases from 0.2 to 0.8, the mu 0Ms of (Sm1_xCex)2Fe17N3 only decreases from 1.52 T to 1.43 T and the anisotropy field gradually decreases from 188 kOe to 49 kOe. Compared with all the existing Fe-based permanent magnets, (Sm,Ce)2Fe17N3 compounds exhibit the superior intrinsic magnetism upon the same Ce substitution level. Magnetically hard anisotropic (Sm1_xCex)2Fe17N3 (x = 0.2-0.6) powders were prepared by surfactant-assisted ball milling. (Sm0.8Ce0.2)2Fe17N3 fine powder shown magnetic properties of mu 0Mr = 1.24 T, HcJ = 9.33 kOe and (BH)max = 28.82 MGOe, which are comparable with Ce-free Sm2Fe17N3. For high Ce-containing (Sm0.4Ce0.6)2Fe17N3 powder, the coercivity can be enhanced significantly from 2.4 kOe to 5.9 kOe by Zn-treatment. These findings suggest the great prospects of Ce-rich (Sm,Ce)2Fe17N3 compounds as a promising alternative material system for high performance magnets.