Amorphous alloy soft magnetic powder, dust core, magnetic element, and electronic device

An amorphous alloy soft magnetic powder comprising:

• a composition represented by (FexCo1−x)100−(a+b)(SiyB1−y)aSb, where
• x, y, a, and b satisfy 0.73≤x≤0.85, 0.02≤y≤0.10, 13.0≤a≤19.0, and 0.7≤b≤1,
• wherein an average particle diameter D50 of the amorphous alloy soft magnetic powder is 5.0 μm or more and 40.0 μm or less,
• wherein a content of Si is 0.50 atomic % or more and 1.40 atomic % or less, and
• wherein a Si—K absorption edge XANES spectrum obtained when performing an XAFS measurement on particles with an analysis depth set to a bulk has
• a peak A present in a range where an energy is 1842±1 eV,
• a peak B present in a range where the energy is 1845±1 eV, and
• a peak C present in a range where the energy is 1848±1 eV, and
• an intensity ratio A/C is 0.40 or less, and an intensity ratio B/C is 0.60 or less where A is an intensity of the peak A, B is an intensity of the peak B, and C is an intensity of the peak C.