A drum-type magnetic body includes: a pair of flange parts that are facing each other; and a shaft part connecting the pair of flange parts, wherein an outer periphery of a cross section of the shaft part in a direction orthogonal to an axis of the shaft part has an oval shape constituted by a pair of parallel straight parts and a pair of arc parts connecting end parts of the pair of parallel straight parts, and the flange parts each have an outer principal face running orthogonal to the axis of the shaft part, and the pair of parallel straight parts are running in parallel with a longitudinal direction of the principal face of the flange part.

An alloy particle contains: total content of Fe and Co: from 82.2 to 96.5 parts by mass; Co: 0 to 30.0 parts by mass; P: 0 to 4.5 parts by mass; B: more than 0 to 5.0 parts by mass; C: 0 to 3.0 parts by mass; Si: 0 to 6.7 parts by mass; Ni: more than 0 to 12.0 parts by mass; Cr: more than 0 to 4.2 parts by mass; total content of Mo, W, Zr, and Nb: 0 to 4.2 parts by mass; total content of P and Cr: 7.4 parts by mass or less; multiplication product of the parts by mass of Ni and Cr: 0.5 or more; and total content of Fe, Co, and Ni: 97.0 parts by mass or less. The alloy particle contains an amorphous phase, and a volume percentage of the amorphous phase is 70% or higher.

An alloy particle contains: total content of Fe and Co: from 82.2 to 96.5 parts by mass; Co: 0 to 30.0 parts by mass; P: 0 to 4.5 parts by mass; B: more than 0 to 5.0 parts by mass; C: 0 to 3.0 parts by mass; Si: 0 to 6.7 parts by mass; Ni: more than 0 to 12.0 parts by mass; Cr: more than 0 to 4.2 parts by mass; total content of Mo, W, Zr, and Nb: 0 to 4.2 parts by mass; total content of P and Cr: 7.4 parts by mass or less; multiplication product of the parts by mass of Ni and Cr: 0.5 or more; and total content of Fe, Co, and Ni: 97.0 parts by mass or less. The alloy particle contains an amorphous phase, and a volume percentage of the amorphous phase is 70% or higher.

A soft magnetic powder containing a particle having a composition represented by Fe.sub.xCu.sub.aNb.sub.b(Si.sub.1-yB.sub.y).sub.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, 75.5≤x≤79.5, and y is a number satisfying f(x)≤y≤0.99, and f(x)=(4×10.sup.−34)x.sup.17.56. The particle includes a crystal grain having a grain size of 1.0 nm or more and 30.0 nm or less and containing a Fe—Si crystal, a Cu segregation portion having a grain size of 2.0 nm or more and 16.0 nm or less in which Cu is segregated, and a crystal grain boundary adjacent to the crystal grain and having a Nb concentration and a B concentration higher than a Nb concentration and a B concentration in the crystal grain. A number proportion of the Cu segregation portion is 80% or more.

A soft magnetic powder containing a particle having a composition represented by Fe.sub.xCu.sub.aNb.sub.b(Si.sub.1-yB.sub.y).sub.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, 75.5≤x≤79.5, and y is a number satisfying f(x)≤y≤0.99, and f(x)=(4×10.sup.−34)x.sup.17.56. The particle includes a crystal grain having a grain size of 1.0 nm or more and 30.0 nm or less and containing a Fe—Si crystal, a Cu segregation portion having a grain size of 2.0 nm or more and 16.0 nm or less in which Cu is segregated, and a crystal grain boundary adjacent to the crystal grain and having a Nb concentration and a B concentration higher than a Nb concentration and a B concentration in the crystal grain. A number proportion of the Cu segregation portion is 80% or more.

Flaky magnetic metal particles of embodiments each have a flat surface and a magnetic metal phase containing iron (Fe), cobalt (Co), and silicon (Si). An amount of Co is from 0.001 at % to 80 at % with respect to the total amount of Fe and Co. An amount of Si is from 0.001 at % to 30 at % with respect to the total amount of the magnetic metal phase. The flaky magnetic metal particles have an average thickness of from 10 nm to 100 μm. An average value of the ratio of the average length in the flat surface with respect to a thickness in each of the flaky magnetic metal particles is from 5 to 10,000. The flaky magnetic metal particles have the difference in coercivity on the basis of direction within the flat surface.

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 dust core including a metal magnetic powder and a resin, in which the metal magnetic powder shows a particle diameter of more than 0 μm and 200 μm or less, a number percentage of 5.0% or more of metal magnetic particles among the metal magnetic particles composing the metal magnetic powder are at least partially surface-coated with an inorganic compound including an alkaline earth metal, in a coating part coating the metal magnetic particles, an amount of the alkaline earth metal is 10.0 mass % or more, when a total amount of a metal element included in the coating part is 100 mass %, is provide. The dust core is superior in a corrosion-resistance.

A dust core including a metal magnetic powder and a resin, in which the metal magnetic powder shows a particle diameter of more than 0 μm and 200 μm or less, a number percentage of 5.0% or more of metal magnetic particles among the metal magnetic particles composing the metal magnetic powder are at least partially surface-coated with an inorganic compound including an alkaline earth metal, in a coating part coating the metal magnetic particles, an amount of the alkaline earth metal is 10.0 mass % or more, when a total amount of a metal element included in the coating part is 100 mass %, is provide. The dust core is superior in a corrosion-resistance.

A wireless charging apparatus according to an embodiment can improve heat dissipation and charging efficiency by adjusting the surface area of a magnetic pad. Therefore, the wireless charging apparatus can be effectively used for a transportation means, such as an electric vehicle, which requires high-capacity power transmission between a transmitter and a receiver.