Permanent magnet, and motor and power generator using the same

摘要

In one embodiment, a permanent magnet includes a sintered compact including: a composition expressed by a composition formula: R p Fe q M r Cu s Co 100-p-q-r-s (R is at least one element selected from rare-earth elements, M is at least one element selected from Zr, Ti, and Hf, 10 ‰¤ p ‰¤ 13.3 at%, 25 ‰¤ q ‰¤ 40 at%, 0.87 ‰¤ r ‰¤ 5.4 at%, and 3.5 ‰¤ s ‰¤ 13.5 at%); and a metallic structure having a main phase including a Th 2 Zn 17 crystal phase, and an R-M-rich phase containing the element R whose concentration is 1.2 times or more an R concentration in the main phase and the element M whose concentration is 1.2 times or more an M concentration in the main phase. A volume fraction of the R-M-rich phase in the metallic structure is from 0.2% to 15%.