A method for producing metal nanowire of small diameter and long length. In the method for producing a metal nanowire, a first solution containing an ionic derivative and a polyol as a solvent are kept at 80-200 C., and a second solution containing a metal salt and a polyol as a solvent is supplied into the first solution so that the ratio between the number of moles of metal atoms in the metal salt supplied in one minute and the total number of moles of halogen atoms in the ionic derivative in the first solution (the number of moles of metal atoms in the metal salt supplied in one minute/the total number of moles of halogen atoms in the ionic derivative) is less than 10. It is preferable that the ionic derivative is a quaternary ammonium halide and the metal salt is silver nitrate.

A method of reducing silver(I) salts to silver nanoparticles employing a carbohydrate reductant in the presence of an inorganic base, a surfactant and optionally a polymer. The method is performed in an aqueous solution at a temperature up to 60? C. and for a duration of up to 40 minutes.

Provided are a flaky-like silver powder having a low bulk density as well as a predetermined average particle size (D.sub.50) and the like, which is obtainable by using a predetermined wet reduction method, a conductive paste obtainable using such a flaky-like silver powder, and a method for producing such a flaky-like silver powder. Disclosed are a flaky-like silver powder obtainable by a wet reduction method, a conductive paste obtainable using a flaky-like silver powder, and a method for producing a flaky-like silver powder, in which the average particle size (D.sub.50) as an equivalent circle diameter obtainable when the flaky-like silver powder particles are viewed planarly is adjusted to a value within the range of 1.1 to 30 m, the thickness of the flaky-like silver powder particles is adjusted to 0.01 to 2 m, and the bulk density of the flaky-like silver powder is adjusted to a value within the range of 0.1 to 4 g/cm.sup.3.

Objects of the invention are to provide a method in which coated metal fine particles are smoothly manufactured when the coated metal fine particles are manufactured using a metal amine complex decomposition method, and, particularly, to provide coated metal fine particles that can be smoothly sintered even at a low temperature. The manufacturing method of coated metal fine particles includes a first step of mixing an amine liquid mixture of an alylamine having 6 or more carbon atoms and an alkylamine having 5 or less carbon atoms with a metal compound including one or more metal atoms, thereby generating a complex compound including the metal compound and amines; and a second step of heating and decomposing the complex compound, thereby generating coated metal fine particles.

A method for manufacturing metal nanoparticles includes adding at least one metal salt to an ionic liquid to form metal ions in the ionic liquid, and heating the ionic liquid to which the metal salt has been added to thermally reduce the metal ions.

Disclosed is a one pot process for the synthesis of ultra-small uniform-sized (1-3 nm) transition metal nanoparticles with shape tunability. These nanoparticles have uses in various fields, including catalysis and fuel cells.

A method is presented for synthesizing particles in the presence of a solid phase. Of note, sorption is used to associate a precursor(s) for synthesizing the particles onto or into the surface of a host structure prior to the chemical reaction that results in the particles being formed in or on surface of the host structure. Particles produced by this method can be stored for long durations and released on-demand in a solvent of choice to form stable suspensions without the need for any additional surfactants or stabilizers.

A silver powder includes a large number of particles. The particles include polyhedral particles 2. The ratio P1 of the number of the polyhedral particles 2 to the total number of the particles is equal to or greater than 80%. Each polyhedral particle 2 has a body containing silver as a main component, and a coating layer covering a surface of the body and containing organic matter as a main component. Each polyhedral particle 2 has an aspect ratio of equal to or less than 3.0. The content P2 of the organic matter in the silver powder is preferably equal to or less than 0.5% by weight. The silver powder preferably has a median diameter D50 of equal to or less than 0.5 m. The silver powder preferably has a tap density TD of equal to or greater than 5.0 g/cm.sup.3.

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 m or more but 6.0 m or less, and a ratio of [(D.sub.90D.sub.10)/D.sub.50] 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.

A complex includes a flat plate-like metal fine particle formed of at least one type of metal or a compound thereof and at least one piece of finely-disintegrated cellulose combined with the flat plate-like metal fine particle. At least a part of each piece of the finely-disintegrated cellulose is incorporated into the flat plate-like metal fine particle, and a remaining part is exposed from a surface of the flat plate-like metal fine particle.