Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one a″-Fe16N2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one a″-Fe16N2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

Provided is an anisotropic magnetic powder having a low oxygen concentration, a small average particle size, a narrow particle size distribution, and a high remanence, and a method for producing the anisotropic magnetic powder. The present disclosure relates to a method for producing an anisotropic magnetic powder, including: pretreating an oxide containing Sm and Fe by heat-treating the oxide in a reducing gas atmosphere to obtain a partial oxide; heat-treating the partial oxide in the presence of a reducing agent to obtain alloy particles; nitriding the alloy particles to obtain a nitride; and treating the nitride with an alkali to obtain a magnetic powder.

Provided is an anisotropic magnetic powder having a low oxygen concentration, a small average particle size, a narrow particle size distribution, and a high remanence, and a method for producing the anisotropic magnetic powder. The present disclosure relates to a method for producing an anisotropic magnetic powder, including: pretreating an oxide containing Sm and Fe by heat-treating the oxide in a reducing gas atmosphere to obtain a partial oxide; heat-treating the partial oxide in the presence of a reducing agent to obtain alloy particles; nitriding the alloy particles to obtain a nitride; and treating the nitride with an alkali to obtain a magnetic powder.

The present application discloses an electrochemiluminescence immunosensor. The immunosensor includes an electrode functionalized by a nanocomposite film. The film further includes carbon nanohorns dispersed in Nafion® perfluorinated resin solution. The polymeric solution is further stabilized by magnetic nanoparticles. The immunosensor is a Point of care (POC)-based. The immunosensor is configured to work in the range from 100 ng/mL to 1 fg/mL, and has tendency to detect even traces of the tropomyosin. The immunosensor is capable to detect traces even less than 1 fg/mL, hence having high specificity for Tro-Ag detection in food products with distinguished repeatability.

A method of producing a magnetic powder includes: performing heat treatment on first particles that contain triiron tetraoxide to prepare second particles that contain ε-iron oxide.

A method of producing a magnetic powder includes: performing heat treatment on first particles that contain triiron tetraoxide to prepare second particles that contain ε-iron oxide.

Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one α″-Fe.sub.16N.sub.2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one α″-Fe.sub.16N.sub.2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

A sintered magnet contains Sm—Fe—N-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 Sm—Fe—N-based crystal grains and a nonmagnetic metal phase present between the Sm—Fe—N 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 Sm—Fe—N-based crystal particles and a nonmagnetic metal layer covering surfaces of the Sm—Fe—N crystal particles.

To obtain a magnetic core having an improved withstand voltage property while maintaining a high relative magnetic permeability, and the like. The magnetic core contains large particles observed as soft magnetic particles having a Heywood diameter of 5 μm or more and 25 μm or less and small particles observed as soft magnetic particles having a Heywood diameter of 0.5 μm or more and less than 5 μm in a cross section. C1<C2 is satisfied in which an average circularity of the small particles close to the large particles is C1 and an average circularity of all small particles observed in the cross section including small particles not close to the large particles is C2. The small particles close to the large particles are defined as small particles whose distance from centroids of the small particles to a surface of the large particles is 3 μm or less.

To obtain a magnetic core having an improved withstand voltage property while maintaining a high relative magnetic permeability, and the like. The magnetic core contains large particles observed as soft magnetic particles having a Heywood diameter of 5 μm or more and 25 μm or less and small particles observed as soft magnetic particles having a Heywood diameter of 0.5 μm or more and less than 5 μm in a cross section. C1<C2 is satisfied in which an average circularity of the small particles close to the large particles is C1 and an average circularity of all small particles observed in the cross section including small particles not close to the large particles is C2. The small particles close to the large particles are defined as small particles whose distance from centroids of the small particles to a surface of the large particles is 3 μm or less.