Permanent magnet, and motor and generator using the same

Abstract

In one embodiment, a permanent magnet includes a sintered compact having a composition represented by the composition formula: RpFeqMrCusCo100-p-q-r-s (where R is at least one element selected from rare earth elements, M is at least one element selected from Zr, Ti, and Hf, p is 10.5 atomic % or more and 12.5 atomic % or less, q is 24 atomic % or more and 40 atomic % or less, r is 0.88 atomic % or more and 4.5 atomic % or less, and s is 3.5 atomic % or more and 10.7 atomic % or less. The sintered compact has a structure having crystal grains constituted of a main phase including a Th2Zn17 crystal phase, and a crystal grain boundary. In the structure of the sintered compact, an average grain diameter of the crystal grains is 25 micrometer or more, and a volume fraction of the crystal grain boundary is 14% or less.

Dependencies are inferred from the claim text.