Patent ID: 8038807

Claim:
A method for producing an R—Fe—B based rare-earth sintered magnet, the method comprising the steps of: providing an R—Fe—B based rare-earth sintered magnet body including, as a main phase, crystal grains of an R 2 Fe 14 B type compound that includes a light rare-earth element RL, which is at least one of Nd and Pr, as a major rare-earth element R; depositing an M layer, including a metallic element M that is at least one element selected from the group consisting of Al, Ga, In, Sn, Pb, Bi, Zn and Ag, on a surface of the R—Fe—B based rare-earth sintered magnet body; depositing an RH layer, including a heavy rare-earth element RH that is at least one element selected from the group consisting of Dy, Ho and Tb, on the M layer; and heating the R—Fe—B based rare-earth sintered magnet body, thereby diffusing the metallic element M and the heavy rare-earth element RH from the surface of the R—Fe—B based rare-earth sintered magnet body deeper inside the magnet.