Disclosed herein is a permanent magnet comprising: a plurality of aligned iron nitride nanoparticles wherein the iron nitride nanoparticles include -Fe.sub.16N.sub.2 phase domains; wherein a ratio of integrated intensities of an -Fe.sub.16N.sub.2 (004) x-ray diffraction peak to an --Fe.sub.16N.sub.2 (202) x-ray diffraction peak for the aligned iron nitride nanoparticles is greater than at least 7%, wherein the diffraction vector is parallel to alignment direction, and wherein the iron nitride nanoparticles exhibit a squareness measured parallel to the alignment direction that is greater than a squareness measured perpendicular to the alignment direction.

A sintered magnet contains SmFeN-based crystal grains and has high coercivity; and a magnetic powder is capable of forming a sintered magnet without lowering the coercivity even if heat is generated in association with the sintering. A sintered magnet comprises a crystal phase composed of a plurality of SmFeN-based crystal grains and a nonmagnetic metal phase present between the SmFeN crystal grains adjacent to each other, wherein a ratio of Fe peak intensity I.sub.Fe to SmFeN peak intensity I.sub.SmFeN measured by an X-ray diffraction method is 0.2 or less. A magnetic powder comprises SmFeN-based crystal particles and a nonmagnetic metal layer covering surfaces of the SmFeN crystal particles.

The claimed invention provides a wet chemical method to prepare manganese bismuth nanoparticles having a particle diameter of 5 to 200 nm. When annealed at 550 to 600K in a field of 0 to 3 T the nanoparticles exhibit a coercivity of approximately 1 T and are suitable for utility as a permanent magnet material. A permanent magnet containing the annealed MnBi nanoparticles is also provided.

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).

A process for producing an ordered martensitic iron nitride powder that is suitable for use as a permanent magnetic material is provided. The process includes fabricating an iron alloy powder having a desired composition and uniformity; nitriding the iron alloy powder by contacting the material with a nitrogen source in a fluidized bed reactor to produce a nitride iron powder; transforming the nitride iron powder to a disordered martensitic phase; annealing the disordered martensitic phase to an ordered martensitic phase; and separating the ordered martensitic phase from the iron nitride powder to yield an ordered martensitic iron nitride powder.

An inductor may include a magnetic material that may include -Fe.sub.16(N.sub.xZ.sub.1-x).sub.2 or -Fe.sub.8(N.sub.xZ.sub.1-x), or a mixture of at least one of -Fe.sub.16N.sub.2 or -Fe.sub.8N and at least one of -Fe.sub.16Z.sub.2 or -Fe.sub.8Z, where Z includes at least one of C, B, or O, and x is a number greater than zero and less than one. In some examples, the magnetic material may include a relatively high magnetic saturation, such as greater than about 200 emu/gram, greater than about 242 emu/gram, or greater than about 250 emu/gram. In addition, in some examples, the magnetic material may include a relatively low coercivity or magnetocrystalline anisotropy. Techniques for forming the inductor including the magnetic material are also described.

A process for producing an ordered martensitic iron nitride powder that is suitable for use as a permanent magnetic material is provided. The process includes fabricating an iron alloy powder having a desired composition and uniformity; nitriding the iron alloy powder by contacting the material with a nitrogen source in a fluidized bed reactor to produce a nitride iron powder; transforming the nitride iron powder to a disordered martensitic phase; annealing the disordered martensitic phase to an ordered martensitic phase; and separating the ordered martensitic phase from the iron nitride powder to yield an ordered martensitic iron nitride powder.

A method may include annealing a material including iron and nitrogen in the presence of an applied magnetic field to form at least one Fe.sub.16N.sub.2 phase domain. The applied magnetic field may have a strength of at least about 0.2 Tesla (T).

Provided is an -iron oxide type ferromagnetic powder with a ratio Hc.sub.173K/Hc.sub.296K between a coercive force Hc.sub.173K measured at a temperature of 173 K and a coercive force Hc.sub.296K measured at a temperature of 296 K is higher than 1.00 and less than 2.00, and a magnetic recording medium containing the -iron oxide type ferromagnetic powder in a magnetic layer.

A method may include annealing a material including iron and nitrogen in the presence of an applied magnetic field to form at least one Fe.sub.16N.sub.2 phase domain. The applied magnetic field may have a strength of at least about 0.2 Tesla (T).