主权项 |
1. A R-T-B based sintered magnet, wherein,
R contains Y and R1 as essential, Y is yttrium, R1 represents at least one rare earth element except Y, and T represents at least one transition metal element containing Fe or the combination of Fe and Co as essential, wherein, the R-T-B based sintered magnet comprises major phase grains with a core portion and a shell portion which covers said core portion, when the mass concentration of Y in the core portion is set as EY, the mass concentration of Y in the shell portion is set as LY and the mass concentration of Y in the R2-Fe14—B crystal grain calculated from the ratio of R1:Y in the total composition is set as SY, the ratio a of EY to SY (EY/SY) is 1.1 or more. |