Fe-base soft magnetic alloy powder and magnetic core thereof and method of producing same

An Fe-base soft magnetic alloy dust core composed of compressed Fe-base soft magnetic alloy fine powder, said Fe-base soft magnetic alloy having the composition represented by the general formula:

• (Fe.sub.1-a M.sub.a).sub.100-x-y-z-.alpha.-.beta.-.gamma. Cu.sub.x Si.sub.y B.sub.z M'.sub..alpha. M".sub..beta. M.sub..gamma.
• wherein M is Co and/or Ni, M' is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, M" is at least one element selected from the group consisting of V, Cr, Mn, Al, elements in the platinum group, Sc, Y, rare earth elements, Au, Zn, Sn and Re, X is at least one element selected from the group consisting of C, Ge, P, Ga, Sb, In, Be and As, and a, x, y, z, .alpha., .beta. and Y respectively satisfy 0<a<0.5, 0.1<x<3, 0<y<30, 0<z<25, 0<y+z<35, 0.1<.alpha.<30, 0<.beta.<10 and 0<.gamma.<10, at least 50% of the alloy structure being fine crystalline particles having an average particle size of 500 .ANG. or less.

The Fe-base soft magnetic alloy dust core according to claim 19, wherein M" is at least one element selected from the group consisting of Ru, Ph, Pd, Os, Ir, Pt, Au, Cr, and V.