Effect of nitrogen content on magnetic properties of Sm/sub 2/Fe/sub 17/N/sub x/ (0<x<6)

Abstract

Effects of nitrogen content on crystal structure and magnetic properties have been investigated in Sm/sub 2/Fe/sub 17/N/sub x/. Sm/sub 2/Fe/sub 17/N/sub x/ specimens with 0<x<6 were prepared by nitrogenation of Sm/sub 2/Fe/sub 17/ in a mixed-gas atmosphere of NH/sub 3/ and H/sub 2/. All of these specimens were confirmed to have the same crystal structure as Sm/sub 2/Fe/sub 17/, although they did not always consist of the single phase. Both saturation magnetization 4 pi I/sub s/ and anisotropy field H/sub a/ took maximum values at x=3.0 (4 pi I/sub s/=15.7 kG, H/sub a/= 260 kOe). Large coercivity was observed in the specimens of fine-grain powders. Anisotropic powder magnets were fabricated by aligning and compacting the fine-grain powders; the highest value of (BH)/sub max/ was 21 MGOe for x=3.0.<<ETX>>