PERMANENT MAGNET, MOTOR USING THE SAME, AND POWER GENERATOR

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PROBLEM TO BE SOLVED : To provide a permanent magnet which enables the improvement of magnetic characteristics such as the magnetization and coercive force of a Sm-Co based sintered magnet. SOLUTION : A permanent magnet comprises a sintered compact having a composition expressed by the compositional 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, and 10≤p≤12.5 atom%, 24≤q≤40 atom%, 0.88≤r≤4.5 atom%, and 3.5≤s≤10.7 atom%). The sintered compact has a structure having crystal grains each including a main phase including a Th2Zn17 type crystal phase and crystal grain boundaries. In the structure of the sintered compact, the average crystal grain diameter of the crystal grains is 25 μm or larger, and the volume fraction of the crystal grain boundaries is 14% or smaller. COPYRIGHT : (C)2015, JPO&INPIT