| 摘要 |
PROBLEM TO BE SOLVED: To provide a rare earth sintered magnet excellent in residual magnetic flux density and coercive force, especially in the coercive force, and having a high squareness ratio, and also to provide a motor and automobile using the rare earth sintered magnet.SOLUTION: A rare earth sintered magnet 10 is equipped with a group of main phase particles 2 of an R-T-B rare earth magnet, each of which has a core 4 and a shell 6 covering the core 4, wherein R contains a heavy rare earth element and a light rare earth element, and a heavy rare earth Cu compound and a light rare earth Cu compound exist on a two-particle boundary in the main phase particle 2 group. In the rare earth sintered magnet 10, a mass ratio of the heavy rare earth compound to the right rare earth Cu compound on the two-particle boundary of a position of 0.3 mm depth from the surface of the rare earth sintered magnet 10, is equal to or less than five times, the mass ratio of the heavy rare earth compound to the light rare earth Cu compound on the two-particle boundary of a position of 1.5 mm depth from the surface of the rare earth sintered magnet 10. |
