R-Fe-B-BASED RARE-EARTH SINTERED MAGNET AND METHOD FOR PRODUCING THE SAME

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PROBLEM TO BE SOLVED : To provide an R-Fe-B-based rare-earth sintered magnet efficiently using a small amount of heavy rare-earth element RH and dispersing it into an outline portion of a main phase crystal grain throughout the entirety of the magnet even when the magnet is relatively thick. SOLUTION : An R-Fe-B-based rare-earth sintered magnet body, which has, as the main phase, R2Fe14B type compound crystal grains containing a light rare-earth element RL (at least one of Nd and Pr) as a main rare-earth element, is first prepared R. Then a layer M which contains a metal element M (at least one selected from the group consisting of Al, Ga, In, Sn, Pb, Bi, Zn and Ag) is deposited on a surface of the sintered magnet body, and an RH layer containing a heavy rare-earth element RH (at least one selected from the group consisting of Dy, Ho and Tb) is deposited on the layer M. Then the sintered magnet body is heated to diffuse the metal element M into the sintered magnet from the surface and also to diffuse the heavy rare-earth element RH into the sintered magnet body from the surface. COPYRIGHT : (C)2012, JPO&INPIT