A composite permanent magnet comprises a first phase including a magnetically hard material and a second phase including a magnetic material. Each of the materials has an anisotropy value selected such that a ratio of the values falls within a predefined range and a resulting grain size of the magnetic material is greater than a predefined threshold defined by the predefined range.

A method of stabilizing soft particles to create dried nanocomposite magnets includes coating a plurality of soft particles with a layer of SiO.sub.2, the soft particles being nanoparticles, creating a composite by mixing the soft particles with hard phase via a solution phase based assembly, annealing the composite, washing the composite with an alkaline solution to remove SiO.sub.2, and compacting the composite to create dried nanocomposite magnets.

A method for producing a nanoheterostructured permanent magnet includes a first step of preparing a raw material solution by dissolving, in a solvent, (1) a block copolymer comprising polymer block components that are immiscible but linked to each other, (2) a first inorganic precursor which is one of a hard magnetic material precursor and a soft magnetic material precursor, and (3) a second inorganic precursor which is the other of the hard magnetic material precursor and the soft magnetic material precursor, and a second step including a phase-separation treatment for forming a nanophase-separated, a conversion treatment for converting the hard magnetic material precursor and the soft magnetic material precursor to a hard magnetic material and a soft magnetic material, respectively, and a removal treatment for removing the block copolymer from the nanophase-separated structure.

Composite magnets such as for electrical machines in vehicles are disclosed. The composite magnets have an interface phase that is different than the magnetically-hard phase and the magnetically-soft phase to ease the transition or create a gradual transition from between the hard and soft phases of the composite magnet. The addition of, for example, an interface layer maintains or enhances performance of the magnetic properties even with higher grain sizes such as beyond the nanoscale level.

A rare-earth magnet containing Sm, Fe, and N contains an Me and B serving as additive elements, the Me representing at least one element selected from elements in groups 4, 5, and 6 of the periodic table, and a nanocomposite microstructure including an Fe phase, a SmFeN phase, and an MeB phase, in which the SmFeN phase includes at least a Sm.sub.2Fe.sub.17N.sub.x phase selected from the Sm.sub.2Fe.sub.17N.sub.x phase and a SmFe.sub.9N.sub.y phase, the volume percentage of the SmFe.sub.9N.sub.y phase in the microstructure is 65% or less by volume, the atomic percentage of the total content of the Me and B is 0.1 at % or more and 5.0 at % or less with respect to the total amount of Sm, Fe, the Me, and B, and the atomic percentage of Fe in all phases of compounds each containing at least one of the Me and B is 20 at % or less.

A composite magnetic material includes a soft magnetic material and a hard magnetic material. The soft magnetic material and the hard magnetic material each contain elemental iron, 90 atom % or more and 100 atom % or less of the elemental iron contained in the soft magnetic material forms a first oxide or a first composite oxide, and 90 atom % or more and 100 atom % or less of the elemental iron contained in the hard magnetic material forms a second oxide or a second composite oxide.

A method of preparing a permanent magnet nanocomposite. The method includes melting a precursor alloy having a hard magnetic phase and a magnetically soft phase. The hard magnetic phase has less than a stoichiometric amount of rare earth metal or noble metal. The melted precursor is cast into flakes and milled into a powder. The powder may then be pressure crystalized.

A method of preparing a permanent magnet nanocomposite. The method melting a precursor alloy having a hard magnetic phase and a magnetically soft phase. The hard magnetic phase has less than a stoichiometric amount of rare earth metal or noble metal. The melted precursor is cast into flakes and milled into a powder. The powder may then be pressure crystallized by pressurizing and heating the powder for a pressurization time. The powder is held at a crystallization temperature and pressure for a hold time to promote crystal growth. Crystal growth may then be rapidly quenched.

A composite permanent magnet comprises a first phase including a magnetically hard material and a second phase including a magnetic material. Each of the materials has an anisotropy value selected such that a ratio of the values falls within a predefined range and a resulting grain size of the magnetic material is greater than a predefined threshold defined by the predefined range.

Disclosed are an anisotropic nanocrystalline rare earth permanent magnet and a preparation method thereof. The rare earth permanent magnet includes an REFeB matrix phase and a second phase, wherein the REFeB matrix phase includes main phase RE.sub.2Fe.sub.14B flaky nanocrystallines regularly arranged and an RE-rich phase around main phase grains, the main phase RE.sub.2Fe.sub.14B flaky nanocrystallines having an average grain size in a length direction of 70 nm to 800 nm and an average grain size in a thickness direction of 30 nm to 200 nm; and the second phase includes at least one selected from the group consisting of an M-Cu phase and an MCuO phase, M being at least one selected from the group consisting of Ca and Mg.