An iron-based oxide magnetic particle powder has a narrow particle size distribution a small content of fine particles that do not contribute to magnetic recording characteristics, and a narrow coercive force distribution, to enhance magnetic recording medium density. Neutralizing an aqueous solution containing a trivalent iron ion and an ion of the metal substituting a part of the Fe sites by adding an alkali to make pH of 1.5 or more and 2.5 or less, adding a hydroxycarboxylic acid, and further neutralizing by adding an alkali to make pH of 8.0 or more and 9.0 or less are performed at 5° C. or more and 25° C. or less. A formed iron oxyhydroxide precipitate containing the substituting metal element is rinsed with water, then coated with silicon oxide, and then heated thereby providing e-type iron-based oxide magnetic particle powder. The rinsed precipitate may be subjected to a hydrothermal treatment.

A soft magnetic powder of the invention has a composition represented by Fe.sub.100-a-b-c-d-e-fCu.sub.aSi.sub.bB.sub.cM.sub.dM′.sub.eX.sub.f (at %) [wherein M is Nb, W, Ta, Zr, Hf, Ti, or Mo, M′ is V, Cr, Mn, Al, a platinum group element, Sc, Y, Au, Zn, Sn, or Re, X is C, P, Ge, Ga, Sb, In, Be, or As, and a, b, c, d, e, and f are numbers that satisfy the following formulae: 0.1≤a≤3, 0<b≤30, 0<c≤25, 5≤b+c≤30, 0.1≤d≤30, 0≤e≤10, and 0≤f≤10], wherein a crystalline structure having a particle diameter of 1 nm or more and 30 nm or less is contained in an amount of 40 vol % or more, and the difference in the coercive force of the powder after classification satisfies predetermined conditions.

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.

The invention discloses a method and its device for preparing a magnetic core with amorphous ribbon. The magnetic core is prepared with amorphous ribbon, the size of the amorphous ribbon is controlled according to the target requirements, and the magnetic core with required size and shape is prepared according to the target requirements; the single-roller rapid quenching technology with online automatic segmentation and automatic storage capability is used for preparation, which can control the length, width and thickness of the amorphous ribbon according to the target requirements; the amorphous ribbon segmented by single-roller rapid quenching technology is used to spray and cool down one by one, and then air-dry, transfer, spray adhesive and online store it one by one; the stored amorphous ribbon is reshaped, compressed and heat-treated successively, and then demoulded to prepare a magnetic core.

The invention discloses a method and its device for preparing a magnetic core with amorphous ribbon. The magnetic core is prepared with amorphous ribbon, the size of the amorphous ribbon is controlled according to the target requirements, and the magnetic core with required size and shape is prepared according to the target requirements; the single-roller rapid quenching technology with online automatic segmentation and automatic storage capability is used for preparation, which can control the length, width and thickness of the amorphous ribbon according to the target requirements; the amorphous ribbon segmented by single-roller rapid quenching technology is used to spray and cool down one by one, and then air-dry, transfer, spray adhesive and online store it one by one; the stored amorphous ribbon is reshaped, compressed and heat-treated successively, and then demoulded to prepare a magnetic core.

A magnetic film includes one or more magnetically conductive layers. Each magnetically conductive layer is cracked to form a plurality of first through-cracks defining a plurality of magnetically conductive segments. The first through-cracks extend along a first direction and form a first regular pattern along an orthogonal second direction at a first pitch P1, such that a Fourier transform of the first regular pattern has a first peak along the second direction at a first spatial frequency corresponding to the first pitch P1. The first through-cracks have an average length L1 along the first direction. L1/P1 is greater than or equal to 5.

A coil component includes: a laminate including a magnetic portion and an insulator, the insulator having a higher insulation quality than the magnetic portion; a first external electrode; a second external electrode; and a coil conductor provided in the laminate, wherein the coil conductor includes a plurality of conductor patterns each extending along a planar direction perpendicular to the coil axis, the plurality of conductor patterns being separated from each other in the direction of the coil axis, the plurality of conductor patterns include a first conductor pattern and a second conductor pattern, the first conductor pattern contacting with the first external electrode, the second conductor pattern contacting with the second external electrode, and in the planar direction, the insulator is provided between the first conductor pattern and the second external electrode and between the second conductor pattern and the first external electrode.

Provided is an amorphous alloy soft magnetic powder having a composition represented by the following formula: (Fe.sub.xCo.sub.(1−x)).sub.(100−(a+b))(Si.sub.yB.sub.(1−y)) .sub.aM.sub.b, [where M is at least one selected from the group consisting of C, S, P, Sn, Mo, Cu, and Nb, 0.73≤x≤0.85, 0.02 ≤y≤0.10, 13.0 ≤a≤19.0, and 0≤b≤2.0], in which a coercive force is 24 [A/m] or more (0.3 [Oe] or more) and 199 [A/m] or less (2.5 [Oe] or less), and a saturation magnetic flux density is 1.60 [T] or more and 2.20 [T] or less.

Provided herein is a soft magnetic alloy powder that can exhibit a high saturation flux density and desirable soft magnetic characteristics. A dust core using such a soft magnetic alloy powder is also provided. A soft magnetic alloy powder is used that includes an amorphous phase, and an αFe crystalline phase residing in the amorphous phase. The αFe crystalline phase has a crystallite volume distribution with a mode of 1 nm or more and 15 nm or less, and with a half width of 3 nm or more and 50 nm or less.