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 100 comprises primary phase grains 4 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 0.8 μm or more and 2.8 μm or less in average particle diameter. The R-T-B based permanent magnet includes at least, C and Zr other than R, T and B. In the R-T-B based permanent magnet, the content of B is 0.75 mass% or more and 0.88 mass% or less and the content of Zr is 0.65 mass% or more and 5.00 mass% or less. The following expression (1) is satisfied : 5.0≤[B]+[C]-[Zr]≤5.6 (1), where [B] is a B content represented by atom%, [C] is a C content represented by atom% and [Zr] is a Zr content represented by atom%. SELECTED DRAWING : Figure 1 COPYRIGHT : (C)2017, JPO&INPIT