A production method for water-atomized metal powder includes: in a region in which the average temperature of a molten metal stream having an Fe concentration of 76.0 at % or more and less than 82.9 at % is 100° C. or more higher than the melting point, spraying primary cooling water at a convergence angle of 10° to 25°, where the convergence angle is an angle between an impact direction on the molten metal stream from one direction and an impact direction on the molten metal stream from any other direction; and in a region in which 0.0004 seconds or more have passed after an impact of the primary cooling water and the average temperature of metal powder is the melting point or higher and (the melting point+100° C.) or lower, spraying secondary cooling water on the metal powder under conditions of an impact pressure of 10 MPa or more.

A production method for water-atomized metal powder includes: in a region in which the average temperature of a molten metal stream having an Fe concentration of 76.0 at % or more and less than 82.9 at % is 100° C. or more higher than the melting point, spraying primary cooling water at a convergence angle of 10° to 25°, where the convergence angle is an angle between an impact direction on the molten metal stream from one direction and an impact direction on the molten metal stream from any other direction; and in a region in which 0.0004 seconds or more have passed after an impact of the primary cooling water and the average temperature of metal powder is the melting point or higher and (the melting point+100° C.) or lower, spraying secondary cooling water on the metal powder under conditions of an impact pressure of 10 MPa or more.

A magnetic material and an inductor capable of attaining both higher magnetic permeability and improved DC superposition characteristics. A composite magnetic material contains metal magnetic particles, in which the metal magnetic particles include first particles having a median diameter D.sub.50 of 1.3 .Math.m or more and 5.0 .Math.m or less (i.e., from 1.3 .Math.m to 5.0 .Math.m), and second particles having a median diameter D.sub.50 larger than the first particles. The first and second particles each include a core portion made of a metal magnetic material, and an insulating film provided on a surface of the core portion. The insulating film of the second particles has an average thickness of 40 nm or more and 100 nm or less (i.e., from 40 nm to 100 nm). The insulating film of the first particles has an average thickness smaller than that of the insulating film of the second particles.

In a magnetic core including a core assembly formed of multiple arranged thin strip blocks, each of the thin strip blocks has a structure that multiple nanocrystalline thin strips having a bcc-Fe phase as a main phase are laminated one above another, and an iron loss in the nanocrystalline thin strip positioned at a center of the thin strip block in a thickness direction thereof is lower than an iron loss in the nanocrystalline thin strip positioned in a surface layer of the thin strip block. The nanocrystalline thin strip may be a heat-treated product of an amorphous thin strip made of an amorphous alloy material, and the thin strip block may include a fixedly joined portion in which the nanocrystalline thin strips adjacent to each other in a lamination direction are fixedly joined together.

In a magnetic core including a core assembly having a structure that multiple thin strip blocks are arranged, the thin strip blocks being formed of multiple laminates of nanocrystalline thin strips made of a nanocrystal-containing alloy material, the thin strip block includes a fixedly joined portion in which the nanocrystalline thin strips adjacent to each other in a lamination direction are fixedly joined together. The fixedly joined portion may include side surfaces of the nanocrystalline thin strips and may be a laser welded portion.

In a magnetic core including a core assembly having a structure that multiple thin strip blocks are arranged, the thin strip blocks being formed of multiple laminates of nanocrystalline thin strips made of a nanocrystal-containing alloy material, the thin strip block includes a fixedly joined portion in which the nanocrystalline thin strips adjacent to each other in a lamination direction are fixedly joined together. The fixedly joined portion may include side surfaces of the nanocrystalline thin strips and may be a laser welded portion.

An Fe-based nano-crystalline alloy formed from an alloy composition of (FeE).sub.(100-X-Y-Z)B.sub.XP.sub.YCu.sub.Z having an amorphous phase as a main phase, wherein 79≦100-X-Y-Z≦86 atomic %, 4≦X≦9 atomic %, 1≦Y≦10 atomic %, and 0.5≦Z<1.2 atomic %, and wherein (FeE) includes Fe and at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Mo, W, Cr, Al, Mn, Ag, Zn, Sn, As, Sb, Bi, Y, N, O and a rare-earth element, wherein a combined total of said at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Mo, W, Cr, Al, Mn, Ag, Zn, Sn, As, Sb, Bi, Y, N, O and a rare-earth element is in an amount of 3 atomic % or less relative to the whole composition.

A magnetic particle includes a magnetic metal particle, and an oxide film formed on a surface of the magnetic metal particle, wherein the magnetic metal particle includes a single crystalline zone containing an Fe component, and the oxide film includes an amorphous zone containing an Fe component. The single crystalline zone may include an α-Fe phase.

Provided is an electromagnetic field shielding plate, etc., in which it is possible to reduce weight while achieving high shielding performance from relatively high-frequency electromagnetic fields. The electromagnetic field shielding plate is configured by layering a permalloy layer 3 comprising a plate or sheet of permalloy, and an amorphous layer 1 comprising an Fe—Si—B—Cu—Nb-based amorphous plate or sheet.

Provided is an electromagnetic field shielding plate, etc., in which it is possible to reduce weight while achieving high shielding performance from relatively high-frequency electromagnetic fields. The electromagnetic field shielding plate is configured by layering a permalloy layer 3 comprising a plate or sheet of permalloy, and an amorphous layer 1 comprising an Fe—Si—B—Cu—Nb-based amorphous plate or sheet.