Patent ID: 11145444

Abstract:
An R-T-B-based sintered magnet 2 contains a rare earth element R, a transition metal element T, B, Ga, and O, the sintered magnet 2 includes a magnet body 4 and an oxidized layer 6 covering the magnet body 4, the magnet body 4 includes main phase grains 8 containing a crystal of R2T14B and a grain boundary phase 1 positioned between the main phase grains 8 and containing R, the oxidized layer 6 includes a plurality of oxide phases 3A containing R, T, Ga, and O, the oxide phase 3A satisfies the following Formulas (1) and (2) regarding the content (unit: atom %) of each element, and the oxide phase 3A in the oxidized layer 6 covers the grain boundary phase 1 in the magnet body 4. 0.3≤[R]/[T]≤0.5  (1)0.2≤[O]/([R]+[T]+[Ga]+[O])≤0.7  (2)