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.

The invention comprises a method for manufacturing an inductor, comprising the steps of: casting a cast winding comprising an inner cavity; inserting a first inductor core subsection into the inner cavity; inserting a second inductor core subsection into the inner cavity; and mechanically coupling the first inductor core subsection to the second inductor core subsection to form an inductor core wound by the cast windings. The method of manufacturing optionally includes the steps of: forming at least a portion of the cast winding into an arced helical shape; forming the first inductor core subsection and the second inductor core subsection into elements of a torpid shaped inductor core; deforming the cast winding to physically allow the step of inserting the first inductor core subsection into the inner cavity; and/or deforming at least a portion of the cast winding into an arced helical coil shape after the step of inserting.

Magnetic particles, each including a core made of a magnetic material, and an insulating coating film which covers a surface of the core made of a magnetic material. The insulating coating film is formed of a sol-gel reaction product of a mixture containing a metal alkoxide and an organic phosphoric acid or a salt thereof.

Magnetic particles, each including a core made of a magnetic material, and an insulating coating film which covers a surface of the core made of a magnetic material. The insulating coating film is formed of a sol-gel reaction product of a mixture containing a metal alkoxide and an organic phosphoric acid or a salt thereof.

Magnetic particles, each including a core made of a magnetic material, and an insulating coating film which covers a surface of the core made of a magnetic material. The insulating coating film is formed of a sol-gel reaction product of a mixture containing a metal alkoxide and an organic phosphoric acid or a salt thereof.

A soft magnetic metal powder includes a coated particle having a soft magnetic metal particle and a coating layer coating a surface of the soft magnetic metal particle. The coating layer contains at least one compound selected from the group consisting of molybdenum disulfide, molybdenum oxide, boron nitride, mica, talc, pyrophyllite, and kaolinite.

A soft magnetic metal powder includes a coated particle having a soft magnetic metal particle and a coating layer coating a surface of the soft magnetic metal particle. The coating layer contains at least one compound selected from the group consisting of molybdenum disulfide, molybdenum oxide, boron nitride, mica, talc, pyrophyllite, and kaolinite.

A magnetic bead reagent contains: a magnetic bead containing a Fe-based metal soft magnetic particle and a silica film that has an average thickness of 20 nm or more and that covers the Fe-based metal soft magnetic particle; a surfactant; and a dispersion medium in which the magnetic bead is dispersed. The surfactant may be a nonionic surfactant.

An element body 4 includes a metal particle dispersion element 15 in which metal particles 12 are dispersed. A surface of the metal particle dispersion element 15 includes an indicator area 10. The indicator area 10 includes a recess 10a having a predetermined depth measured from a reference plane L of the metal particle dispersion element 15. The predetermined depth D1 is deeper than D50 of the metal particles 12 included in the metal particle dispersion element 15.