Magnetic Properties of Sm-Fe-Co System Nitrided Compounds

Experiments were carried out to investigate the effect of cobalt substitution on the magnetic and physical properties of Sm2Fe17 nitrided compounds. Sm2(Fe1-xCox)17 nitrided compounds (x=0 to 0.3) were prepared by heat treating fine powders of Sm2(Fe1-xCox)17 alloys in N2 gas at a pressure of 4.9 MPa. X-ray diffraction patterns revealed these nitrided compounds to have a Th2Zn17-type structure. Sm2(Fe1-xCox)17 alloys were observed to absorb the same large amount of nitrogen as Sm2Fe17 alloy. The Curie temperatures of these nitrided compounds increases with increasing Co content, and the lattice constants a and c decrease slightly. The intrinsic coercivity of 652.5 kA/m (8.20 kOe) and Curie temperature of 556°C were achieved for an Sm2(Fe0.8Co0.2)17N3.1 compound.