Takahiro Hirai

Structural and magnetic properties of rapidly quenched (R,Zr)(Fe,Co)10Nx (R=Nd,Sm)

The structural and magnetic properties of (R,Zr)(Fe,Co)10(R=Nd,Sm) prepared by the rapid‐quenching method have been investigated. The presence of zirconium makes it possible to realize a TbCu7‐type crystal structure with a high c/a ratio of more than 0.87, while the same crystal structure has a c/a ratio of just 0.84–0.85 in the zirconium‐free case. The saturation magnetization of crystals having such a high c/a ratio as 0.87 exceeds 1.7 T at room temperature. These materials can be nitrogenated, and remarkable enhancement of magnetocrystalline anisotropy by nitrogenation can be seen in the case of Sm. The magnetic hardening of these nitrogenated materials can be achieved by annealing before nitrogenation. The highest value of (BH)max obtained so far for the nitrogenated materials is 144 kJ/m3 (18.0 MGOe). The iHc and Br values for this sample are 503 kA/m (6.3 kOe) and 1.08 T, respectively.