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 crystalline Fe-based alloy powder composed of Fe-based alloy particles containing, within a structure thereof, nanocrystal grains having an average grain size of 30 nm or less, and in which d50, which is a particle diameter corresponding to a cumulative frequency of 50% by volume, is from 3.5 μm to 35.0 μm in a cumulative distribution curve that is obtained by laser diffractometry and that shows the relationship between the particle diameter and the cumulative frequency from the small particle diameter side, and a ratio of Fe-based alloy particles having a particle diameter of 2 μm or less to the total of the Fe-based alloy particles, which is determined by laser diffractometry, is from 0% by volume to 8% by volume.

Implementations described herein provide systems and methods for wireless charging. In one implementation, a base has a planar surface. One or more posts extend from the planar surface of the base to form a core. Each of the one or more posts is formed from a plurality of nanocrystalline sheets. The plurality of nanocrystalline sheets of each of the one or more posts is oriented in planes perpendicular to the planar surface of the base. One or more coils are wound around each of the one or more posts to form coil windings.

A coil electronic component includes a support substrate, a coil pattern disposed on at least a surface of the support substrate and having a core region in the center of the coil pattern, at least one metal thin plate disposed on an upper portion of the coil pattern and having a shape bent toward the core region, an encapsulant sealing at least a portion of the support substrate, the coil pattern, and the at least one metal thin plate, and an external electrode disposed outside of the encapsulant and connected to the coil pattern.

A nanocrystalline magnetic conductive sheet for wireless charging and a preparation method therefor are provided. The nanocrystalline magnetic conductive sheet includes a composition of Fe.sub.(100-x-y-z-α-β-γ)M.sub.xCu.sub.yM′.sub.zSi.sub.αB.sub.βX.sub.γ, saturation magnetic induction is greater than or equal to 1.25 T. The preparation method includes preparing an alloy with a preset composition of into an alloy strip with an initial state of amorphousness by a single roll rapid quenching method, annealing an amorphous alloy strip according to a preset annealing process, to obtain a nanocrystalline strip, performing a magnetic fragmentation process on the nanocrystalline strip, to obtain the nanocrystalline magnetic conductive sheet for wireless charging.

A soft magnetic alloy includes a composition of (Fe.sub.(1-(α+β))X1.sub.αX2.sub.β).sub.(1-(a+b+c+d+e+f+g))M.sub.aTi.sub.bB.sub.cP.sub.dSi.sub.eS.sub.fC.sub.g. X1 is one or more of Co and Ni. X2 is one or more of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O, and rare earth elements. M is one or more of Nb, Hf, Zr, Ta, Mo, W, and V. 0.020≤a+b≤0.140, 0.001≤b≤0.140, 0.020<c≤0.200, 0.010≤d≤0.150, 0≤e≤0.060, a≥0, f≥0, g≥0, a+b+c+d+e+f+g<1, α≥0, β≥0, and 0≤α+β≤0.50 are satisfied. The soft magnetic alloy has a nanohetero structure or a structure of Fe-based nanocrystalline.

There is provided a method for producing metal foils, capable of easily crystalizing amorphous soft magnetic material of a plurality of metal foils into nano-crystal soft magnetic material by uniformly heating the metal foils. A laminate obtained by laminating the metal foils made of amorphous soft magnetic material is held by a holding member such that adjacent metal foils can be separated from each other in a laminated direction of the laminate. By conveying either the holding member or magnets in a direction perpendicular to the laminated direction as a conveying direction such that the holding member and the magnets come close to each other, the adjacent metal foils are separated from each other with a magnetic force of the magnets. The separated metal foils are heated to crystalize the amorphous soft magnetic material of the metal foils into nano-crystal soft magnetic material. The same magnetic pole of the magnets aligns in the laminated direction.

There is provided a soft magnetic powder containing soft magnetic metal particles satisfying the following formulas (A) (B), and (C),

S=k{6/(d.Math.ρ)}  (A)

1.0≤k≤4.0  (B)

1.0≤d≤10.0  (C)

in which S [m.sup.2/g] indicates a specific surface area, d [μm] indicates an average particle diameter, and ρ [g/cm.sup.3] indicates a true specific gravity.

A soft magnetic alloy or the like combining high saturated magnetic flux density, low coercive force and high magnetic permeability μ′ having the composition formula (Fe.sub.(1−(α+β))X1.sub.αX2.sub.β).sub.(1−(a+b+c+d+e))B.sub.aSi.sub.bC.sub.cCu.sub.dM.sub.e. X1 is one more elements selected from the group consisting of Co and Ni, X2 is one or more elements selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Bi, N, O and rare earth elements, and M is one or more elements selected from the group consisting of Nb, Hf, Zr, Ta, Ti, Mo, W and V. 0.140<a≤0.240, 0≤b≤0.030, 0<c<0.080, 0<d≤0.020, 0≤e≤0.030, α≥0, β≥0, and 0≤α+β≤0.50 are satisfied.

A soft magnetic core of an inductor or a motor core includes an alloy having a composition of Fe, Si, B, P, Cu, and Y, and the soft magnetic core or the motor core has a composite structure in which crystal grains including Fe are dispersed in an amorphous phase. Also, the alloy is expressed by the compositional formula Fe.sub.aSi.sub.bB.sub.cP.sub.dCu.sub.eY.sub.fC.sub.g, wherein a to g satisfy 80≤a≤87, 0≤b≤9, 3≤c≤14, 1≤d≤8, 0.2≤e≤2.5, 0≤f≤3.0, 0≤g≤4.0, and 0≤(e/f)≤4 in terms of atomic percentage value.