R-T-B based sintered magnet

摘要

The present invention provides an R-T-B based sintered magnet including R2T14B crystal grains wherein; a grain boundary is formed by two or more adjacent R2T14B crystal grains, an R—O—C concentrated part, in which concentrations of R, O and C are higher than those in the R2T14B crystal grains respectively, is in the grain boundary, and an area of the R—O—C concentrated part occupying in that of the grain boundary on a cut surface of the R-T-B based sintered magnet is within a range of 10% or more to 75% or less.

主权项

1. An R-T-B based sintered magnet comprising R2T14B crystal grains and grain boundaries formed by two or more adjacent R2T14B crystal grains, wherein:
R represents at least one rare earth element; T represents at least one transition metal element comprising Fe or Fe and Co; the grain boundaries comprise R—O—C concentrated parts; the R—O—C concentrated parts are entire areas of the grain boundaries have concentrations of R, O, and C that are higher than concentrations of R, O, and C in the R2T14B crystal grains; an average area ratio of the total R—O—C concentrated parts to the entire grain boundaries is within a range of 14% or more to 71% or less, and an average ratio (O/R) of O atom to R atom in the R—O—C concentrated parts is within a range of 0.41 or more to 0.70 or less.