| 摘要 |
This sintered R-T-B based rare-earth magnet includes: R 2 Fe 14 B type compound crystal grains, including a light rare-earth element RL (which includes at least one of Nd and Pr) as a major rare-earth element R, as main phases; and a heavy rare-earth element RH (which includes at least one of Dy and Tb). Before its surface region is removed, the sintered R-T-B based rare-earth magnet has no layer including the rare-earth element R at a high concentration in that surface region. The sintered R-T-B based rare-earth magnet has a portion in (which coercivity decreases gradually from its surface region toward its core portion. The difference in the amount of TRE between a portion of the sintered R-T-B based rare-earth magnet that reaches a depth of 500 µm as measured from its surface region toward its core portion and the core portion of the sintered R-T-B based rare-earth magnet is 0.1 through 1.0. |
