Patent ID: 7311788

Claim:
An R-T-B system rare earth permanent magnet, comprising a main phase consisting of an R 2 T 14 B 1 phase (wherein R represents one or more rare earth elements (provided that the rare earth elements include Y), and T represents at least one transition metal element containing, as a main constituent, Fe, or Fe and Co), and a grain boundary phase containing a higher total amount of R than said main phase, said R-T-B system rare earth permanent magnet being a sintered body having a composition consisting essentially of 28% to 33% by weight of R, 0.5% to 1.5% by weight of B, 0.03% to 0.3% by weight of Al, 0.3% or less (excluding 0) by weight of Cu, 0.05% to 0.2% by weight of Zr, 4% or less by weight (excluding 0) of Co 0.2% or less by weight of oxygen, and the balance substantially being Fe, said sintered body containing a region that is rich both Cu and Zr.