R-T-B BASED PERMANENT MAGNET

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PROBLEM TO BE SOLVED : To provide an R-T-B based permanent magnet which allows a high coercive force to be achieved even if the amount of use of a heavy rare earth element is reduced. SOLUTION : An R-T-B based permanent magnet according to the present invention comprises primary phase grains of an R2T14B type compound, where R is a rare earth element, T is Fe, or any of iron group elements including Fe and Co as essential elements, and B is boron. The primary phase grains are 2.8 μm or smaller in average particle diameter. The R-T-B based permanent magnet includes at least, C and Ga other than R, T and B. In the R-T-B based permanent magnet, the content of B is 0.71 mass% or more and 0.86 mass% or less, the content of C is 0.13 mass% or more and 0.34 mass% or less and the content of Ga is 0.40 mass% or more and 1.80 mass% or less. The following expression (1) is satisfied : 0.14≤[C]/([B]+[C])≤0.30 (1), where [B] is a B content represented by atom%, and [C] is a C content represented by atom%. SELECTED DRAWING : Figure 1 COPYRIGHT : (C)2017, JPO&INPIT