Rare-earth cobalt permanent magnet, manufacturing method therefor, and device

A rare-earth cobalt permanent magnet consisting of 23 to 27 mass % of a rare-earth element R, 4.0 to 5.0 mass % of Cu, 22 to 24.5 mass % of Fe, 1.7 to 2.5 mass % of Zr, and a remainder consisting of Co and unavoidable impurities, wherein the rare-earth element R consists of Sm, and wherein

• the rare-earth cobalt permanent magnet includes a plurality of crystal grains and grain boundary parts,
• a size of a cell structure constituting the crystal grain is 250 to 600 nm,
• an intrinsic coercive force Hcj is equal to or larger than 1,600 kA/m,
• when the intrinsic coercive force Hcj and a magnitude of a reverse magnetic field when a residual magnetic flux density Br is 90% is represented by Hk, a ratio Hk/Hcj is equal to or higher than 65%, and
• a maximum energy product (BH)m thereof is equal to or larger than 275 kJ/m3 at 20° C.