Magnetic Properties and Structure of Nitrogenated R2(Fe,Co)17 IntermetallicCompounds

摘要

Nitrogenation of Y2Fel7, Gd2Fel7 an SM2(Fe1-yCoy)17 systems has been investigatedin the temperature range from 573 to 873 K. The optimum nitrogen absorbed in the R2Fel7 system is around 2.5 to 2.7 atoms per formula unit. Lattice parameters and volume expansion coefficients all increase with increasing nitrogen content. Nitrogenation increases the saturation magnetization at 4.2 K from 34.7 Of Y2Fe17 to 40.3 micron B/f.u. of Y2Fel7N2.6, from 22.9 of Gd2Fel7 to 30.3 micronB/f.U. of Gd2Fel7N2.5 and from 28.3 of Sm2Fel7 to 35.2 micronB/f.u. of SM2Fel7N2.6. The increase of the saturation magnetization is less effective in the Co-containing SM2(FeCo)17 alloys. A significant improvement on the magnetic anisotropy has been observed in the Sm2(Fe1-yCoy)17Nx system. Magnetic anisotropy alters from planar to axial for Y = 0, 0.2 and 0.4 and x = 2.6 to 2.7. The anisotropy field increases from 34 kOe of Sm2(Fe0.4Co0.6)17 to 62 kOe of Sm2(Fe0.4Co0.6)17N23 at 295 K. Magnetics and Structures, Nitrogenated R2(Fe,Co)17.