A sintering powder comprising copper particles, wherein: the particles are at least partially coated with a capping agent, and the particles exhibit a D10 of greater than or equal to 100 nm and a D90 of less than or equal to 2000 nm.

Disclosed herein are coated copper particles formed of copper cores that are surface coated with a coating composition comprising one or more conductive oxides. Further disclosed herein are electrically conductive adhesives (ECA) comprising: (a) organic binder, (b) surface coated copper particles, and optional (c) solvent.

Provided herein are methods of preparing three-dimensional photonic crystals having tunable optical properties and control over stopband location and width, the three-dimensional photonic crystals comprising nanoparticles and spacer groups.

A metal particle aggregate includes metal particles and an organic substance. The metal particles include first particles that contain one or both of silver and copper in an amount of 70% by mass or more relative to 100% by mass of all metals and have a particle diameter of 100 nm or more and less than 500 nm at a ratio of 20 to 30% by number, and include second particles that have a particle diameter of 50 nm or more and less than 100 nm, and third particles that have a particle diameter of less than 50 nm at a ratio of 80 to 70% by number in total. Surfaces of the first to third particles are covered with the same protective film.

A bonded soft magnet object comprising bonded soft magnetic particles of an iron-containing alloy having a soft magnet characteristic, wherein the bonded soft magnetic particles have a particle size of at least 200 nm and up to 100 microns. Also described herein is a method for producing the bonded soft magnet by indirect additive manufacturing (IAM), such as by: (i) producing a soft magnet preform by bonding soft magnetic particles with an organic binder, wherein the magnetic particles have an iron-containing alloy composition with a soft magnet characteristic, and wherein the particles of the soft magnet material have a particle size of at least 200 nm and up to 100 microns; (ii) subjecting the preform to an elevated temperature sufficient to remove the organic binder to produce a binder-free preform; and (iii) sintering the binder-free preform at a further elevated temperature to produce the bonded soft magnet.

A low viscosity polysulfide sealant composition. The composition comprises a curable polysulfide polymer; a crosslinking agent; and a plurality of core-shell particles. The core-shell particles comprise: a core comprising a ferromagnetic material; and a shell comprising silica treated with an organic sulfur containing compound. The shell is capable of bonding with the polysulfide polymer.

A low viscosity polysulfide sealant composition. The composition comprises a curable polysulfide polymer; a crosslinking agent; and a plurality of core-shell particles. The core-shell particles comprise: a core comprising a ferromagnetic material; and a shell comprising silica treated with an organic sulfur containing compound. The shell is capable of bonding with the polysulfide polymer.

To provide novel low-temperature sinterable copper particles that can be sintered even at a low temperature of, for example, around 100 C. or less, and a method for producing a sintered body by using the same. The low-temperature sinterable copper particles according to the present invention are coated with a carboxylic acid, and a surface of the copper particle is oxidized so as to have a cuprous oxide fraction (Cu.sub.2O/(Cu+Cu.sub.2O)) in the copper particle of 4% by mass or less or so as to have an average coating thickness of cuprous oxide of 10 nm or less. The low-temperature sinterable copper particles are subjected to low-temperature firing in an atmosphere of 0.01 Pa or less.

A process for producing nickel powder capable of obtaining inexpensive, and also, high-performance nickel powder, even when using wet process. A process for producing nickel powder, including a crystallization step for obtaining nickel crystal powder by reductive reaction in reaction solution in which at least water-soluble nickel salt, metal salt of metal more noble than nickel, reducing agent, alkali hydroxide, amine compound, and water are mixed, wherein the reducing agent to be mixed in the crystallization step is hydrazine, the amine compound is autolysis inhibitor of hydrazine, and contains two or more primary amino groups in molecule, or contains one primary amino group and one or more secondary amino groups in molecule, and ratio of molar number of the amine compound with respect to molar number of nickel in the reaction solution is in a range of 0.01 mol % to 5 mol %.

Disclosed herein are a solder alloy composition comprising SnBiIn base solder particles. The SnBiIn base solder particles is characterized by having an average diameter less than 10 m, and the SnBiIn base alloy comprises 12-22% of Sn, 33-43% of Bi and 45-55% by weight. Also disclosed herein is a method for producing the SnBiIn base solder particles. The method mainly includes the steps of, sintering a mixture comprising tin (Sn), bismuth (Bi) and indium (In) at a designated weight ratio to produce a bulk alloy; dissolving the bulk alloy to produce an alloy solution; and subjected the alloy solution to ultrasonication at a first temperature of about 65-85 C. and then cooling at a second temperature of about 0-25 C., thereby produces the present SnBiIn base solder particles.