| 摘要 |
PURPOSE: To provide a low-cost magnet having high coercive force, high rectangular ratio and high energy product. CONSTITUTION: A magnet contains R (R is one or more types of rare earth elements, the Sm ratio in the R is 50 atomic % or more), T (Fe or Fe and Co), N and M (Zr or the part of Zr is substituted with one or more types of Ti, V, Cr, Nb, Hf, Ta, Mo, W, Al, C and P), wherein R amount is 4 to 8 atomic %, N amount is 10 to 20 atomic %, M amount is 2 to 10 atomic % and the residue is substantially T. In the magnet, there exists a hard magnetic phase containing R, T and N as main bodies and including one or more types of crystalline phases of TbCu7 type, Th2 Zn17 type and Th2 Ni17 type and soft magnetic phase made of T phase of bcc structure, wherein the mean crystalline grain size of the soft magnetic phase is 5 to 60nm, and the ratio of the soft magnetic phase is 10 to 60vol.%. With this structure, high coercive force is obtained, its rectangular ratio is high and high maximum energy product is realized. |
