Provided is soft magnetic powder used to manufacture a dust core having good mechanical strength and superior formability while iron loss is reduced. The soft magnetic powder for dust cores according to the invention is soft magnetic mixed powder that includes pure iron powder and soft magnetic iron-base alloy powder, wherein the proportion of the soft magnetic iron-base alloy powder in the mixture is 5 to 60 mass %, the ratio of the modes of the particle size distributions of the soft magnetic iron-base alloy powder and the pure iron powder ((the mode of the particle size distribution of the soft magnetic iron-base alloy powder)/(the mode of the particle size distribution of the pure iron powder)) is 0.9 or more and less than 5, and the ratio R.sub.over/R.sub.under is 1.2 or more, where R.sub.over is the mass proportion of soft magnetic iron-base alloy powder in mixed powder with a particle size of D50 or more based on the mass fraction, and R.sub.under is the mass proportion of soft magnetic iron-base alloy powder in mixed powder with a particle size of less than D50 based on the mass fraction.

A magnetic powder is represented by general formula Fe.sub.a(Si.sub.bB.sub.cP.sub.d).sub.100-a, and is produced with a gas atomization method. When the value of a and the value of b in the general formula is represented (a, b), (a, b) is within a predetermined region V1. Similarly, (a, c) and (a, d) are within a predetermined region, respectively. Whereby, it is possible to obtain an alloy magnetic powder which has high saturation magnetic flux density, low magnetic loss, and is spherical and easy to handle; and a magnetic core, a variety of coil components, and a motor can be realized by using the magnetic material.

A magnetic powder is represented by general formula Fe.sub.aSi.sub.bB.sub.cP.sub.dCu.sub.e. 71.0≦a≦81.0, 0.14≦b/c≦5, 0≦d≦14, 0<e≦1.4, d≦0.8a−50, e<−0.1(a+d)+10, and a+b+c+d+e=100. A crystallinity is not more than 30% in the case of containing an amorphous phase and a compound phase, and is not more than 60% in the case of not containing a compound phase. The magnetic powder is produced with a gas atomization method. Whereby, it is possible to obtain an alloy magnetic material which has high saturation magnetic flux density and low magnetic loss; and a magnetic core, coil components, and a motor can be realized.

A silver powder, including: an organic substance on a surface of the silver powder, the organic substance containing at least one carboxyl group and at least one hydroxyl group in one molecule of the organic substance, wherein a BET specific surface area of the silver powder is 0.1 m.sup.2/g or more but 2.0 m.sup.2/g or less, and wherein a cumulative 50% point of particle diameter (D.sub.50) of the silver powder in a volume-based particle size distribution of the silver powder as measured by a laser diffraction particle size distribution analysis is 0.1 μm or more but 6.0 μm or less, and a ratio of [(D.sub.90−D.sub.10)/D.sub.5o] is 3.0 or less, where D.sub.50 is the cumulative 50% point of particle diameter, D.sub.90 is a cumulative 90% point of particle diameter of the silver powder, and D.sub.10 is a cumulative 10% point of particle diameter of the silver powder.

The present invention provides an alloy fine particle including palladium and ruthenium, the alloy fine particle including at least one first phase in which the palladium is more abundant than the ruthenium and at least one second phase in which the ruthenium is more abundant than the palladium, the at least one first phase and the at least one second phase being separated by a phase boundary, the palladium and the ruthenium being distributed in the phase boundary in such a manner that the molar ratio of the palladium and the ruthenium continually changes, a plurality of crystalline structures being present together in the phase boundary.

A permanent magnet includes R and T (R essentially includes Sm one or more of rare earth elements in addition to Sm, and T essentially includes Fe, or Fe and Co, one or more of transition metal elements in addition to Fe, or Fe and Co). A composition ratio of R in the permanent magnet is 20 at % or more and 40 at % or less. A remaining part is substantially only T, or only T and C. T amount is more than 1.5 times of R amount and less than 4.0 times of the R amount. Main phase grains included in the permanent magnet have an Nd5Fe17 type crystal structure. An average crystal grain size of the main phase grains of the permanent magnet is greater than 1 μm. A number ratio of main phase grains having a crystal grain size of less than 0.4 μm is less than 20%.

A permanent magnet includes R and T (R essentially includes Sm one or more of rare earth elements in addition to Sm, and T essentially includes Fe, or Fe and Co, one or more of transition metal elements in addition to Fe, or Fe and Co). A composition ratio of R in the permanent magnet is 20 at % or more and 40 at % or less. A remaining part is substantially only T, or only T and C. T amount is more than 1.5 times of R amount and less than 4.0 times of the R amount. Main phase grains included in the permanent magnet have an Nd5Fe17 type crystal structure. An average crystal grain size of the main phase grains of the permanent magnet is greater than 1 μm. A number ratio of main phase grains having a crystal grain size of less than 0.4 μm is less than 20%.

To provide a metal-based structure or nanoparticles whose homogeneity is not deteriorated and whose sticking formation is easy, and a production method thereof with a high safety. A metal-based structure comprises a hydrogen compound, cluster, or an aggregate thereof, represented by the general formula: M.sub.mH. The M is a metal-based atom. The m is an integer of 3 or more and 300 or less. H is a hydrogen atom.

A production method for water-atomized metal powder includes: in a region in which the average temperature of a molten metal stream is higher than the melting point by 100° C. or more, spraying primary cooling water from a plurality of directions at a convergence angle of 10° to 25°, where the convergence angle is an angle between an impact direction on the molten metal stream of the primary cooling water from one direction and an impact direction on the molten metal stream of the primary cooling water from any other direction; and in a region in which 0.0004 seconds or more have passed after an impact of the primary cooling water and the average temperature of metal powder is the melting point or higher and (the melting point+50° C.) or lower, spraying secondary cooling water on the metal powder under conditions of an impact pressure of 10 MPa or more.

A production method for water-atomized metal powder includes: in a region in which the average temperature of a molten metal stream having an Fe concentration of 76.0 at % or more and less than 82.9 at % is 100° C. or more higher than the melting point, spraying primary cooling water at a convergence angle of 10° to 25°, where the convergence angle is an angle between an impact direction on the molten metal stream from one direction and an impact direction on the molten metal stream from any other direction; and in a region in which 0.0004 seconds or more have passed after an impact of the primary cooling water and the average temperature of metal powder is the melting point or higher and (the melting point+100° C.) or lower, spraying secondary cooling water on the metal powder under conditions of an impact pressure of 10 MPa or more.