MAGNETIC-PROPERTIES OF SM-ND-FE-CO-N COMPOUNDS AND MAGNETIC VISCOSITY OF THEIR BONDED MAGNETS

(Sm1-xNdx)(2)(Fe0.8Co0.2)(17)N-y (x = 0-0.5) compounds were prepared by nitrogenation of (Sm1-xNdx)(2)(Fe0.8Co0.2)(17) alloy powders (about 30 mu m in size) in high purity nitrogen gas at a pressure of 4.9 MPa and a temperature of 500-600 degrees C for 1.5-3.0 h. The anisotropy field (H-A) and the saturation magnetization (J(s)) of these samples were measured with magnetically aligned powders. The anisotropy field in (Sm1-xNdx)(2)(Fe0.8Co0.2)(17)N-y compounds decreased linearly with increasing x value, while the saturation magnetization increased. It was found that the H-A and: J(s) values of (Sm0.9Nd0.1)(2)(Fe0.8Co0.2)(17)N-3.07 were 10.1 MA m(-1) and 193.6 x 10(-6) Wb . m kg(-1) respectively. Anisotropic epoxy-bonded magnets were prepared from (Sm0.9Nd0.1)(2)(Fe0.8Co0.2)(17)N-3.07 powder about 3-5 mu m in size by a compressing molding process. The magnetic properties of a typical bonded magnet were (BH)(max)=101.8 kJ m(-3) J(T)=0.89 T, H-c,=394 kA m(-1) and H-cB=314 kA m(-1). The magnetic viscosity of this bonded magnet was measured. The magnetic viscosity coefficient (S-V) and the activation volume (V) of this bonded magnet were 2.39 kA m(-1) and 13.3 X 10(-25) m(3) respectively.