Permanent magnet, rotary electric machine, and vehicle
AssigneeKabushiki Kaisha Toshiba
InventorsMasaya Hagiwara, Shinya Sakurada, Keiko Okamoto
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Abstract
A permanent magnet comprises a plurality of crystal grains having a main phase of an R-Fe-B magnetic phase, R being at least one element selected from the group consisting of Nd, Pr, Dy, Tb, and Ho. A grain size distribution of the crystal grains satisfies a formula: d10<Rc<d90, the Rc indicating a single-domain critical grain size of the magnetic phase, the d10 indicating a grain size in which a cumulative frequency ratio in the grain size distribution is 10%, and the d90 indicating a grain size in which a cumulative frequency ratio in the grain size distribution is 90%.
Claims12
A permanent magnet comprising
- a plurality of crystal grains having a main phase of an R-Fe-B magnetic phase, R being at least one element selected from the group consisting of Nd, Pr, Dy, Tb, and Ho,
- wherein a grain size distribution of the crystal grains satisfies a formula:
- d10<Rc<d90, the Rc indicating a single-domain critical grain size of the magnetic phase, the d10 indicating a grain size in which a cumulative frequency ratio in the grain size distribution is 10%, and the d90 indicating a grain size in which a cumulative frequency ratio in the grain size distribution is 90%.
Dependencies are inferred from the claim text.