Patent ID: 11823824

Abstract:
The present disclosure includes a main phase comprising an R2T14B compound, and a grain boundary phase. The atom number ratio of B to T in this R-T-B sintered magnet is less than the atom number ratio of B to T in the stoichiometric composition of the R2T14B compound, and the relationships 26.0 mass %≤([Nd]+[Pr]+[Ce]+[Dy]+[Tb])−(9×[O]+12×[C])≤27.5 mass %, 0.15 mass %≤[O]≤0.30 mass %, and 0.05 mass %<[Tb]≤0.35 mass % are satisfied, where [Nd] is the Nd content (mass %), [Pr] is the Pr content (mass %), [Ce] is the Ce content (mass %), [Dy] is the Dy content (mass %), [O] is the O content (mass %), and [C] is the C content (mass %). Tb concentration and/or the Dy concentration gradually decreases from the magnet surface toward the magnet interior, at least in part.