| 摘要 |
PROBLEM TO BE SOLVED: To provide a permanent magnet with a light weight without remarkably decreasing a coercivity, as compared with conventional R-T-B based magnets.SOLUTION: A core-shell structure is formed for a major phase grain by adding Cu to an R-T-B based magnet which is a raw material. When the mass concentration of Y in a core portion is denoted as EY, the mass concentration of Y in a shell portion is denoted as LY and the mass concentration of Y in an R-Fe-B crystal grain calculated from the ratio R1:Y in the total composition is denoted as SY, the ratio (α=EY/SY) of EY to SY is 1.1 or more. Thus, the magnetic insulation among the crystal grains becomes better, so that a decrease of coercivity due to the addition of Y is prevented. Further, the addition of Y makes the magnet lighter in weight. |
