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: 0.1a3, 0<b30, 0<c25, 5b+c30, 0.1d30, 0e10, and 0f10], 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 m to 35.0 m 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 m 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.

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: 0.1a3, 0<b30, 0<c25, 5b+c30, 0.1d30, 0e10, and 0f10], 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.

An amorphous alloy soft magnetic powder contains a particle having a composition with a compositional formula (Fe.sub.1-xCr.sub.x) a (Si.sub.1-yB.sub.y).sub.100-a-bC.sub.b expressed by an atomic ratio, in which 0<x?0.06, 0.3?y?0.7, 70.0?a?81.0, and 0<b?3.0, and when XAFS measurement is performed with an analysis depth set to a bulk, an obtained FeK absorption edge XANES spectrum has a first absorption edge structure having a peak A present in a range of 7113?1 eV and a first continuous band structure positioned at a higher energy side than the first absorption edge structure, and an intensity of the peak A at 7113 eV is 0.60 or more and 0.90 or less when an intensity of the first continuous band structure is 1.

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.

A method for producing a soft magnetic material having both high saturation magnetization and low coercive force, including: preparing an alloy having a composition represented by Compositional Formula 1 or 2 and having an amorphous phase, and heating the alloy at a rate of temperature rise of 10 C./sec or more and holding for 0 to 80 seconds at a temperature equal to or higher than the crystallization starting temperature and lower than the temperature at which FeB compounds start to form wherein, Compositional Formula 1 is Fe.sub.100-x-yB.sub.xM.sub.y, M represents at least one element selected from Nb, Mo, Ta, W, Ni, Co and Sn, and x and y are in atomic percent (at %) and satisfy the relational expressions of 10x16 and 0y8, and Compositional Formula 2 is Fe.sub.100-a-b-cB.sub.aCu.sub.bM.sub.c, M represents at least one element selected from Nb, Mo, Ta, W, Ni and Co, and a, b and c are in atomic percent (at %) and satisfy the relational expressions 10a16, 0<b2 and 0c8.

A Continuous Ultra-Rapid Annealing (CURA) method for producing a nanocrystalline alloy is provided. The method includes placing amorphous ribbons on a first reel, preheating a Cu wheel to a temperature of about 750? K to about 800? K, and unwinding the amorphous ribbons from the first reel to a second reel. The methods include directly contacting the amorphous ribbons between the first reel and the second reel with the Cu wheel for a length of time and under tension to produce the nanocrystalline alloy. The methods include winding the nanocrystalline alloy on the second reel.

An amorphous alloy soft magnetic powder contains a particle having a composition with a compositional formula (Fe.sub.1-xCr.sub.x) a (Si.sub.1-yB.sub.y).sub.100-a-bC.sub.b expressed by an atomic ratio, in which 0<x?0.06, 0.3?y?0.7, 70.0?a?81.0, and 0<b?3.0, and when XAFS measurement is performed with an analysis depth set to a bulk, an obtained FeK absorption edge XANES spectrum has a first absorption edge structure having a peak A present in a range of 7113?1 eV and a first continuous band structure positioned at a higher energy side than the first absorption edge structure, and an intensity of the peak A at 7113 eV is 0.60 or more and 0.90 or less when an intensity of the first continuous band structure is 1.

A soft magnetic powder including a core containing a soft magnetic metal material and an insulating film covering the surface of the core. The insulating film contains an insulating metal oxide and an iron component, and the iron component is embedded in the insulating film.

Provided is a soft magnetic alloy including Fe as a main component, in which a slope of an approximate straight line, plotted between cumulative frequencies of 20 to 80% on Fe content in each grid of 80000 grids or more, each of which has 1 nm1 nm1 nm, is 0.1 to 0.4, provided that Fe content (atom %) of each grid is Y axis, and the cumulative frequencies (%) obtained in descending order of Fe content in each grid is X axis, and an amorphization ratio X is 85% or more.