To provide a method for producing surface-modified metal oxide fine particles, which can produce surface-modified metal oxide fine particles having excellent dispersion stability in dispersion liquids having various compositions; a method for producing improved metal oxide fine particles, suitable as a method for producing metal oxide fine particles to be surface-modified in production of the surface-modified metal oxide fine particles; surface-modified metal oxide fine particles which can be produced by the method for producing surface-modified metal oxide fine particles; and a metal oxide fine particle dispersion liquid including the surface-modified metal oxide fine particles. Surface-modified metal oxide fine particles are produced by a method including coating at least a part of surfaces of metal oxide fine particles with a carboxylic acid compound having a certain structure substituted with an amino group which may be cyclic, and/or carboxylate thereof.

A method includes depositing a layer of alloy particles including rare earth permanent magnet phase above a substrate, laser scanning the layer while cooling the substrate to melt the particles, selectively initiate crystal nucleation, and promote columnar grain growth in a same direction as an easy axis of the rare earth permanent magnet phase. The method also includes repeating the depositing and scanning to form bulk anisotropic rare earth alloy magnet with aligned columnar grains.

A step of, while a powder of an RLM alloy (where RL is Nd and/or Pr; M is one or more elements selected from among Cu, Fe, Ga, Co, Ni and Al) which is produced through atomization and a powder of an RH compound (where RH is Dy and/or Tb) are present on the surface of a sintered R-T-B based magnet, performing a heat treatment at a sintering temperature of the sintered R-T-B based magnet or lower is included. The RLM alloy contains RL in an amount of 65 at % or more, and the melting point of the RLM alloy is equal to or less than the temperature of the heat treatment. The heat treatment is performed while the RLM alloy powder and the RH compound powder are present on the surface of the sintered R-T-B based magnet at a mass ratio of RLM alloy:RH compound=9.6:0.4 to 5:5.

A carbon-coated metal powder having few impurities, a narrower particle size distribution, and sintering properties is particularly suitable as a conductive powder of a conductive paste for forming internal conductors in a ceramic multilayer electronic component obtained by co-firing multilayered ceramic sheets and internal conductor layers; a conductive paste containing the carbon-coated metal powder; a multilayer electronic component using the conductive paste; and a method for manufacturing the carbon-coated metal powder. The carbon-coated metal powder has specific properties in TMA or ESCA measurements. The carbon-coated metal powder can be obtained by melting and vaporizing a metallic raw material in a reaction vessel, conveying the generated metal vapor into a cooling tube and rapidly cooling the metal vapor by endothermically decomposing a carbon source supplied into the cooling tube, and forming a carbon coating film on metal nuclei surfaces in parallel with generation of the metal nuclei.

A carbon-coated metal powder having few impurities, a narrower particle size distribution, and sintering properties is particularly suitable as a conductive powder of a conductive paste for forming internal conductors in a ceramic multilayer electronic component obtained by co-firing multilayered ceramic sheets and internal conductor layers; a conductive paste containing the carbon-coated metal powder; a multilayer electronic component using the conductive paste; and a method for manufacturing the carbon-coated metal powder. The carbon-coated metal powder has specific properties in TMA or ESCA measurements. The carbon-coated metal powder can be obtained by melting and vaporizing a metallic raw material in a reaction vessel, conveying the generated metal vapor into a cooling tube and rapidly cooling the metal vapor by endothermically decomposing a carbon source supplied into the cooling tube, and forming a carbon coating film on metal nuclei surfaces in parallel with generation of the metal nuclei.

The invention relates to a method for producing a composite material consisting of a metal and ceramic alloy, comprising steps of: producing a mixture of metal powder and ceramic powder, the particle size of the metal powder being micrometric and the particle size of the ceramic powder being nanometric; and exposing said mixture to a focused energy source that selectively fuses part of a bed of said powder mixture.

A step is provided which performs a heat treatment at the sintering temperature of a sintered R-T-B based magnet or lower, while a powder of an RLM alloy (where RL is Nd and/or Pr; M is one or more selected from among Cu, Fe, Ga, Co and Ni) and a powder of an RH fluoride (where RH is Dy and/or Tb) are present on a surface of the sintered R-T-B based magnet. The RLM alloy contains RL in an amount of 50 at % or more, and a melting point of the RLM alloy is equal to or less than a temperature of the heat treatment. The heat treatment is performed while the RLM alloy powder and the RH fluoride powder are present on the surface of the sintered R-T-B based magnet at a mass ratio of RLM alloy:RH fluoride=96:4 to 5:5.

Methods for the manufacture of fine metal powders from metal carboxylate compounds such as metal oxalate compounds. The method includes decomposing particulates of the metal oxalate compound by heating to a decomposition temperature in the presence of a dilute hydrogen gas to decompose the metal oxalate compound, and forming a fine metal powder by heating to a higher refining temperature to remove contaminants from the metal powder. The method may include the conversion of a non-oxalate metal compound to a hydrated metal oxalate and the dehydration of the hydrated metal oxalate before decomposition to the metal. The method is applicable to the production of a wide variety of metals, and is particularly applicable to the production of rare earth metals of high purity and fine particle size.

A method of making a physical unclonable function (PUF) having magnetic and non-magnetic particles is disclosed. Measuring both magnetic field and image view makes the PUF difficult to counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other methods are disclosed.

A magnet structure includes columnar grains of rare earth permanent magnet phase aligned in a same direction and arranged to form bulk anisotropic rare earth alloy magnet having a boundary defined by opposite ends of the columnar grains and lacking triple junction regions, and rare earth alloy diffused onto opposite ends of the bulk anisotropic rare earth alloy magnet.