R-T-B BASED SINTERED MAGNET

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The present invention provides a permanent magnet with both a high corrosion resistance and magnetic properties compared to the existing R-T-B based magnets. It is a R-T-B based sintered magnet (wherein, R includes Y (yttrium) and R1 as essential, R1 is at least one kind of rare earth elements except Y but includes Nd as e essential, and T is one or more kinds of transition metal elements including Fe or the combination of Fe and Co as essential). By allowing the ratio of R1 to Y (R1 : Y) in the R to be 80 : 20˜35 : 65 according to the molar ratio of the sintered magnet composition, Y segregates at the triple point, and corrosion of grain boundary phase is prevented by oxidizing it.