Soft magnetic powder, dust core, magnetic element, and electronic device

A soft magnetic powder comprising:

• a particle having a composition represented by FexCuaNbb (Si1-yBy)100-x-a-b,
• a, b, and x being numbers whose units are atomic %, in which
• 0.3≤a≤2.0,
• 2.0≤b≤4.0, and
• 73.0≤x≤79.5, and
• y being a number satisfying f(x)≤y≤0.99, and f(x)=(4×10−34)x17.56, wherein
• the particle contains a crystal grain having a grain size of 1.0 nm or more and 30.0 nm or less,
• when an XPS spectrum of the particle is obtained by X-ray photoelectron spectroscopy and fitting processing of separating an O1s peak of the XPS spectrum into a plurality of different chemical states is performed,
• the O1s peak is separated into at least one first element peak having a peak top binding energy of 532 eV or less and at least one second element peak having a peak top binding energy of more than 532 eV,
• S2/S1 is 1.5 or more, where S1 is a total area of the first element peak and S2 is a total area of the second element peak,
• the first element peak is indicative of the composition containing at least one of oxygen and a hydroxy group bonded to metal, and
• the second element peak is indicative of the composition containing at least one of silicon oxide and carbon oxide, and
• when a cylindrical green compact with an inner diameter of 8 mm and a mass of 0.7 g is formed using the soft magnetic powder and the green compact is compressed in an axial direction under a load of 20 kgf, a resistance value of the green compact in the axial direction is 0.3 kΩ or more and 30.0 kΩ or less.