Abstract: The present invention provides a sintered magnet having superior residual magnetic flux density and coercive force. The sintered magnet of the present invention comprises a group of R-T-B based rare earth magnet crystal particles 2 having a core 4 and a shell 6 covering the core 4, the mass ratio of a heavy rare earth element in the shell 6 is higher than the mass ratio of a heavy rare earth element in the core 4, and the thickest part of the shell 6 in the crystal particles 2 faces a grain boundary triple junction 1. A lattice defect 3 is formed between the core 4 and the shell 6.

Abstract: An R-T-B based sintered magnet maintains high magnetic properties and decreases usage of heavy rare earth elements. The magnet includes main phase grains and grain boundary phases, the main phase grain containing a core portion and a shell portion. X in the main phase LR(2-x)HRxT14B of the core portion ranges from 0.00 to 0.07; x in the main phase LR(2-x)HRxT14B of the shell portion ranges from 0.02 to 0.40; and the maximum thickness of the shell portion ranges from 7 nm to 100 nm. LR contains Nd and one or more light rare earth elements consisting of Y, La, Ce, Pr and Sm; HR contains Dy or/and Tb and one or more heavy rare earth elements consisting of Gd, Ho, Er, Tm, Yb and Lu; T contains Fe or/and Co and one or two kinds of Mn and Ni; and B represents boron partly replaced by C (carbon).

Abstract: The present invention provides a rare earth based sintered magnet. The magnet is a rare earth based permanent magnet with a R-T-B (R represents one or more elements selected from Y and rare earth elements, T represents one or more metal elements including Fe or the combination of Fe and Co, and B represents B or the combination of B and C) based composition. When a R-rich phase (R represents rare earth element(s)) with atomic ratio of (Fe+Co)/(LR+HR+Fe+Co)?0.2 (LR represents Y and light rare earth element(s) selected from 57La to 63Eu, and HR represents heavy rare earth element(s) selected from 64Gd to 71Lu) is present in the grain boundary triple point, a region with HR/(LR+HR)?0.01 (atomic ratio) is present in the R-rich phase, and the region with HR/(LR+HR)?0.01 accounts for 10% to 90% of the area of the grain boundary triple point.

Abstract: The present invention provides a rare earth based sintered magnet. The magnet is a rare earth based permanent magnet with a R-T-B (R represents one or more elements selected from Y and rare earth elements, T represents one or more metal elements including Fe or the combination of Fe and Co, and B represents B or the combination of B and C) based composition. When a R-rich phase (R represents rare earth element(s)) with atomic ratio of (Fe+Co)/(LR+HR+Fe+Co)?0.2 (LR represents Y and light rare earth element(s) selected from 57La to 63Eu, and HR represents heavy rare earth element(s) selected from 64Gd to 7ILu) is present in the grain boundary triple point, a region with HR/(LR+HR)?0.01 (atomic ratio) is present in the R-rich phase, and the region with HR/(LR+HR)?0.01 accounts for 10% to 90% of the area of the grain boundary triple point.

Abstract: An R-T-B based sintered magnet maintains high magnetic properties and decreases usage of heavy rare earth elements. The magnet includes main phase grains and grain boundary phases, the main phase grain containing a core portion and a shell portion. X in the main phase LR(2-x)HRxT14B of the core portion ranges from 0.00 to 0.07; x in the main phase LR(2-x)HRxT14B of the shell portion ranges from 0.02 to 0.40; and the maximum thickness of the shell portion ranges from 7 nm to 100 nm. LR contains Nd and one or more light rare earth elements consisting of Y, La, Ce, Pr and Sm; HR contains Dy or/and Tb and one or more heavy rare earth elements consisting of Gd, Ho, Er, Tm, Yb and Lu; T contains Fe or/and Co and one or two kinds of Mn and Ni; and B represents boron partly replaced by C (carbon).

Abstract: The present invention provides a sintered magnet having superior residual magnetic flux density and coercive force. The sintered magnet of the present invention comprises a group of R-T-B based rare earth magnet crystal particles 2 having a core 4 and a shell 6 covering the core 4, the mass ratio of a heavy rare earth element in the shell 6 is higher than the mass ratio of a heavy rare earth element in the core 4, and the thickest part of the shell 6 in the crystal particles 2 faces a grain boundary triple junction 1. A lattice defect 3 is formed between the core 4 and the shell 6.

Abstract: The invention provides an R-T-B rare earth sintered magnet 100 including R2T14B-containing crystal grains as the main phase 10, and having an RL-T-M1 based compound 12 at the grain boundary triple points, wherein R represents a rare earth element, T represents at least one element selected from among Fe, Co and Cu, B represents boron, RL represents a light rare earth element, and M1 represents at least one element selected from among Al, Zn and Ga.

Abstract: The invention provides a process for producing a magnet that not only allows satisfactory Br and HcJ values to be achieved but can also yield a magnet with a sufficiently large squareness ratio. The process for producing a magnet according to the invention is characterized by comprising a first step in which a heavy rare earth compound containing a heavy rare earth element is adhered onto a rare earth magnet sintered compact, and a second step in which the heavy rare earth compound-adhered sintered compact is subjected to heat treatment. The heavy rare earth compound is a hydride of the heavy rare earth element.