Abstract: An R-T-B permanent magnet that contains: main-phase grains composed of an R2T14B compound (where R is a rare earth element, T is a transition metal element, and B is boron); and grain boundaries. R includes Ce. The grain boundaries include multi-grain grain boundaries that are adjacent to three or more main-phase grains. The multi-grain grain boundaries include an R-rich phase, and lamellar or acicular R-T precipitates are present in the R-rich phase.

Abstract: An R-T-B-based permanent magnet including: R (rare earth element); T (Fe and Co); B (boron); and one or more selected from Al, Cu, Ga, and Zr. R includes Ce. The total R content is 31.3-34.0 mass % (inclusive), the Co content is 1.85-3.00 mass % (inclusive), the B content is 0.80-0.90 mass % (inclusive), the Al content is 0.03-0.90 mass % (inclusive), the Cu content is 0-0.25 mass % (inclusive), the Ga content is 0-0.10 mass % (inclusive), the Zr content is 0-0.60 mass % (inclusive), and the Fe content is substantially the remainder. The Ce content relative to R is 15-25 mass % (inclusive).

Abstract: An R-T-B permanent magnet that contains: main-phase grains composed of an R2T14B compound (where R is a rare earth element, T is a transition metal element, and B is boron); and grain boundaries. R includes Ce. The R-T-B permanent magnet has a Ce content of 15-35 mass % with respect to the total R content. The grain boundaries include an R-rich phase and an R-T phase. In a cross section of the R-T-B permanent magnet, the surface area ratio S(R-T) of the R-T phases with respect to the grain boundaries is 0.60-0.85.

Abstract: To provide an alloy for an R-T-B based permanent magnet from which an R-T-B based permanent magnet having improved magnetic properties can be manufactured. The alloy for an R-T-B based permanent magnet contains R, T, and B, in which R is a rare earth element, T is a transition metal element, and B is boron. An area ratio of a non-columnar crystal structure in a cross section is 1.0% or more and 30.0% or less.

Abstract: A permanent magnet includes Nd, Fe, B, and Ga and contains a first T rich phase 1, a second T rich phase 3, and a T poor phase 5 as grain boundary phases, the first T rich phase 1 satisfies 1.7?[T]/[R]?3.0, the second T rich phase 3 satisfies 0.8?[T]/[R]?1.5, the T poor phase 5 satisfies 0.0?[T]/[R]?0.6, and the following Formulas 4 and 5 are satisfied. [T] represents the concentration (atom %) of Fe and Co, [R] represents the concentration (atom %) of Nd, Pr, Tb, and Dy, S1 represents the area of the first T rich phase 1 exposed at a cross-section of the permanent magnet, S2 represents the area of the second T rich phase 3 exposed at the cross-section, and S3 represents the area of the T poor phase 5 exposed at the cross-section. 0.30?(S1+S2)/(S1+S2+S3)?0.80??(4) 0.20?S2/(S1+S2)?0.

Abstract: A permanent magnet includes Nd, Fe, B, and Ga and contains a first T rich phase 1, a second T rich phase 3, and a T poor phase 5 as grain boundary phases, the first T rich phase 1 satisfies 1.7?[T]/[R]?3.0, the second T rich phase 3 satisfies 0.8?[T]/[R]?1.5, the T poor phase 5 satisfies 0.0?[T]/[R]?0.6, and the following Formulas 4 and 5 are satisfied. [T] represents the concentration (atom %) of Fe and Co, [R] represents the concentration (atom %) of Nd, Pr, Tb, and Dy, S1 represents the area of the first T rich phase 1 exposed at a cross-section of the permanent magnet, S2 represents the area of the second T rich phase 3 exposed at the cross-section, and S3 represents the area of the T poor phase 5 exposed at the cross-section. 0.30?(S1+S2)/(S1+S2+S3)?0.80??(4) 0.20?S2/(S1+S2)?0.

Abstract: A sintered magnet contains a rare earth element R (Nd), a transition metal element T (Fe), and B, Cu, and Ga, the sintered magnet includes a plurality of main phase grains (R2T14B crystal grains) and a plurality of grain boundary multiple junctions surrounded by three or more main phase grains, the plurality of grain boundary multiple junctions are classified into a transition metal rich phase (for example, R6T13Ga) and an R-rich phase, the R-rich phase is classified into a Cu-poor phase and a Cu-rich phase, and the following Formulas 1 and 2 are satisfied in a cross section of the sintered magnet. N1 is the number of transition metal rich phases, N2 is the number of Cu-poor phases, and N3 is the number of Cu-rich phases. 0.30?N1/(N1+N2+N3)?0.60 ??(1) 0.03?N3/N2?0.