An R-T-B based permanent magnet excellent in magnetic properties relatively reduces the amount of a heavy rare earth element used. An R-T-B based permanent magnet, wherein R represents a rare earth element, T an iron group element and B boron, includes main phase grains including an R.sub.2T.sub.14B crystal phase and grain boundaries formed between main phase grains. Grain boundaries include R-O-C-N concentrated parts where concentrations of R, O, C and N are all higher than those in main phase grains. C/R(S)>C/R(C) is satisfied in which C/R(S) represents a C/R ratio (atomic ratio) in R-O-C-N concentrated parts present in a surface of a R-T-B based permanent magnet and C/R(C) represents a C/R ratio (atomic ratio) in the R-O-C-N concentrated parts present in the center of a R-T-B based permanent magnet, and a heavy rare earth element RH is included in the R-T-B based permanent magnet.

A method for manufacturing a raw magnet includes manufacturing a first raw form from a first magnetic base material; manufacturing a second raw form from a second magnetic base material; and applying an external magnetic field to at least one raw form selected from a group consisting of the first raw form and the second raw form during and/or after manufacturing of the raw form. A third raw form is manufactured from the first raw form and the second raw form by joining them together. The third raw form is sintered and the raw magnet is obtained.

A magnetic core has a high initial permeability and a small core loss, reducing a core loss at high frequencies; and a coil component including the same. This magnetic core is formed by binding a plurality of Fe-based alloy particles containing Al via an oxide layer containing an Fe oxide. In an X-ray diffraction spectrum of the magnetic core measured using Cu-K characteristic X-rays, a peak intensity ratio (P1/P2) of peak intensity P1 of a diffraction peak derived from the Fe oxide having a corundum structure appearing in the vicinity of 2=33.2 to peak intensity P2 of a diffraction peak derived from the Fe-based alloy having a bcc structure appearing in the vicinity of 2=44.7 is 0.010 or less (excluding 0). A superlattice peak intensity of an Fe.sub.3Al ordered structure is at most a noise level within a range of 2=20 to 40.

The present invention provides an R-T-B based sintered magnet that inhibits the demagnetization rate at high temperature even when less or no heavy rare earth elements such as Dy, Tb and the like are used. The R-T-B based sintered magnet includes R.sub.2T.sub.14B crystal grains and two-grain boundary parts between the R.sub.2T.sub.14B crystal grains. Two-grain boundary parts formed by RCoCu-M-Fe phase exist, and M is at least one selected from the group consisting of Ga, Si, Sn, Ge and Bi.

A rare earth-iron-nitrogen-based magnetic powder according to this invention contains, as main constituent components, a rare-earth element (R), iron (Fe), and nitrogen (N). Moreover, this magnetic powder has an average particle size of 1.0-10.0 ?m, and contains 22.0-30.0 mass % of a rare-earth element (R) and 2.5-4.0 mass % of nitrogen (N). Further, this magnetic powder includes: a core part having any one crystal structure among a Th.sub.2Zn.sub.17 type, a Th.sub.2Ni.sub.17 type, and a TbCu.sub.7 type; and a shell layer provided on the surface of the core part and having a thickness of 1-30 nm. The shell layer contains a rare-earth element (R) and iron (Fe) so that the R/Fe atomic ratio is 0.3-5.0, and further contains 0-10 at % (exclusive of 0) of nitrogen (N). Furthermore, this magnetic powder contains compound particles composed of a rare-earth element (R) and phosphorus (P).

The permanent magnet includes: a main phase expressed by a composition formula: RM.sub.ZN.sub.X and having at least one crystal structure selected from the group consisting of a Th.sub.2Ni.sub.17 crystal structure, a Th.sub.2Zn.sub.17 crystal structure, and a TbCu.sub.7 crystal structure; and a sub phase having a phosphorus compound phase containing a phosphorus compound excluding a phosphoric acid compound.

New types of particle feedstocks and heterogeneous grain structures are provided for rare earth permanent magnets (REPMs) and their production in a manner to significantly enhance toughness of the magnet with little or no sacrifice in the hard magnetic properties. The novel tough REPMs made from the feedstock have heterogeneous grain structures, such as bi-modal, tri-modal, multi-modal, laminated, gridded, gradient fine/coarse grain structures, or other microstructural heterogeneity and configurations, without changing the chemical compositions of magnets.

New types of particle feedstocks and heterogeneous grain structures are provided for rare earth permanent magnets (REPMs) and their production in a manner to significantly enhance toughness of the magnet with little or no sacrifice in the hard magnetic properties. The novel tough REPMs made from the feedstock have heterogeneous grain structures, such as bi-modal, tri-modal, multi-modal, laminated, gridded, gradient fine/coarse grain structures, or other microstructural heterogeneity and configurations, without changing the chemical compositions of magnets.

A method for producing a permanent or soft magnet including the following steps: a) providing: a solution containing a solvent in which are dispersed a set of objects which possess a permanent magnetic moment; a substrate on which are fixed to the surface or within a cavity that it may have, a 1st pad and a 2nd pad, said 1st pad includes a face facing and parallel to a face that the 2nd pad includes; b) the solution is deposited on the surface of the substrate or, as the case may be, within its cavity; c) the substrate is placed in a magnetic field so that the set of objects are grouped together between the face of the 1st pad and the face of the 2nd pad so as to form a permanent magnet.

A method for producing a sintered R-T-B based magnet of this disclosure includes the steps of preparing a plurality of sintered R-T-B based magnet bodies (R is at least one of rare earth elements and necessarily contains Nd and/or Pr; and T is at least one of transition metals and necessarily contains Fe); preparing a plurality of alloy powder particles having a size of 90 m or less and containing a heavy rare earth element RH (the heavy rare earth RH is Tb and/or Dy) at a content of 20 mass % or greater and 80 mass % or less; loading the plurality of sintered R-T-B based magnet bodies and the plurality of alloy powder particles of a ratio of 2% by weight or greater and 15% by weight or less with respect to the plurality of sintered R-T-B based magnet bodies into a process chamber; and heating, while rotating and/or swinging, the process chamber to move the sintered R-T-B based magnet bodies and the alloy powder particles continuously or intermittently to perform an RH supply and diffusion process.