RARE EARTH PERMANENT MAGNET

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PROBLEM TO BE SOLVED : To provide a high performance R-Fe-B based permanent magnet imparting high coercive force (R is two kinds or more selected from rare earth elements including Sc and Y). SOLUTION : In a sintered magnet body having R1aR2bTcAdFeOfMg composition, constitutional elements of F and R2 are distributed such that the concentration of component increases in average from the center toward the surface of the magnet body, and a grain boundary where the concentration of R2/(R1+R2) is higher in average than that in a main phase crystal grains consisting of tetragonal (R1, R2)2T14A continues down to a depth of at least 10 μm from the surface of the magnet in three-dimensional mesh shape. COPYRIGHT : (C)2007, JPO&INPIT