A composite particle comprises a core, a shielding layer deposited on the core, and further comprises an interlayer region formed at an interface of the shielding layer and the core, the interlayer region having a reactivity less than that of the core, and the shielding layer having a reactivity less than that of the interlayer region, a metallic layer not identical to the shielding layer and deposited on the shielding layer, the metallic layer having a reactivity less than that of the core, and optionally, an adhesion metal layer deposited on the metallic layer, wherein the composite particles have a corrosion rate of about 0.1 to about 450 mg/cm.sup.2/hour using an aqueous 3 wt % KCl solution at 200° F. An article comprises composite particles, wherein has a corrosion rates of about 0.1 to about 450 mg/cm.sup.2/hour using an aqueous 3 wt % KCl solution at 200° F.

A core-shell nanoparticle is provided that includes a core comprising a first isotope of an element; an isolation layer surrounding the core; and a shell layer surrounding the isolation layer, wherein the shell layer comprises a second isotope of the element, with the first isotope being different than the second isotope. Methods are also provided for forming such core-shell nanoparticles.

Described herein is a radiation shielding composition and a method for making comprising: (i) a boron-containing powder wherein the boron-containing powder comprises at least a bimodal particle size distribution, and (ii) a metal, wherein the metal encapsulates the ceramic powder to form the radiation shielding composition.

A conductive particle including a conductive powder, a conductive polymer composition, and an anisotropic conductive sheet, each of which has a particularly smaller volume resistivity and better conductivity than those of the related art, and is desirably inexpensive. A conductive particle includes a first plating layer (pure Ni plating layer or Ni plating layer containing 4.0 mass % or less of P) covering the surface of a spherical Ni core containing 5 mass % to 15 mass % or less of P. The conductive particle may further include a Au plating layer having a thickness of from 5 nm to 200 nm and covering the surface of the first plating layer.

A preparation method for a silver-metal oxide electrical contact material, comprising: (1) mixing a silver-containing precursor solution with a metal oxide precursor solution; (2) reacting a reducing agent with the mixed solution to obtain silver powder coated with a metal oxide precursor; (3) heat treating the silver powder in a non-reducing atmosphere to obtain the silver-metal oxide electrical contact material. A preparation device for a silver-metal oxide electrical contact material, a silver-metal oxide electrical contact material prepared by the preparation method, and an electrical contact prepared by the silver-metal oxide electrical contact material. The electrical contact material prepared by the preparation method is at nanoscale, significantly prolonging electrical endurance of the electrical contact.

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 μm. The silver powder preferably has a tap density TD of equal to or greater than 5.0 g/cm.sup.3.

According to various aspects and embodiments, multilayer particles having an irregular surface architecture and methods of making the same are disclosed.

A method for producing a magnetic powder includes performing a reduction treatment on the surface of particles including a hard magnetic material to form core-shell particles each having a shell portion including a soft magnetic material.

Provided is a solder material having oxidation resistance at the time of melting solder or after melting it, as well as managing a thickness of oxide film at a fixed value or less before melting the solder. A Cu core ball 1A is provided with a Cu ball 2A for keeping a space between a semiconductor package and a printed circuit board and a solder layer 3A that covers the Cu ball 2A. The solder layer 3A is composed of Sn or a solder alloy whose main component is Sn. For the Cu core ball 1A, lightness is equal to or more than 65 in the L*a*b* color space and yellowness is equal to or less than 7.0 in the L*a*b* color space, and more preferably, the lightness is equal to or more than 70 and the yellowness thereof is equal to or less than 5.1.

A disintegrable powder compact includes a matrix; a plurality of dispersed particles including a particle core material dispersed in the matrix; a ferrous alloy including carbon disposed in one of the matrix or particle core material; and a secondary element disposed in the other of the matrix or particle core material, the matrix and the plurality of dispersed particles having different standard electrode potentials. A process for preparing a disintegrable powder compact includes combining a primary particle including a ferrous alloy that includes carbon and a secondary particle to form a composition; compacting the composition to form a preform; and sintering the preform by forming a matrix, wherein the dispersed particles are dispersed in the matrix, the disintegrable powder compact is configured to disintegrate in response to contact with a disintegration fluid, and the primary particle and secondary particle have different standard electrode potentials.