Abstract: A method for preparing a highly crystallized metal powder, comprising: supplying at least one heat-decomposable metal compound powder into a reaction vessel using a carrier gas; and forming a metal powder by heating the metal compound powder in a state in which the metal compound powder is dispersed in a gas phase at a concentration of no more than 10 g/liter, at a temperature that is over the decomposition temperature of the metal compound powder and at least (Tm−200)° C. when the melting point of the metal contained in the metal compound powder is Tm° C. The method provides a high-purity, high-density, highly dispersible, fine, highly crystallized metal powder consisting of spherical particles of uniform size, which is suited to use in thick film pastes, and particularly conductor pastes and the like used in the preparation of multilayer ceramic electronic parts.

Abstract: A method for preparing a highly crystallized metal powder, involving the steps of: supplying at least one heat-decomposable metal compound powder into a reaction vessel using a carrier gas; and forming a metal powder by heating the metal compound powder in a state in which the metal compound powder is dispersed in a gas phase at a concentration of no more than 10 g/liter, at a temperature that is over the decomposition temperature of the metal compound powder and at least (Tm −200)° C. when the melting point of the metal contained in the metal compound powder is Tm° C. The method provides a high-purity, high-density, highly dispersible, fine, highly crystallized metal powder consisting of spherical particles of uniform size, which is suitable for use in thick film pastes, and particularly conductor pastes and the like used in the preparation of multilayer ceramic electronic parts.

Abstract: Nickel composite particles having a layer of a nickel-containing spinel on at least a part of the surface of nickel particles, or nickel composite particles having an oxide layer of metals other than nickel on at least a part of the surface of nickel particles and a layer of a nickel-containing spinel at an interface between the nickel particles and the metal oxide layer. The nickel composite particles are produced by forming fine liquid droplets from a solution containing (a) at least one thermally decomposable nickel compound and (b) at least one thermally decomposable metal compound capable of forming a spinel together with nickel; and heating the liquid droplets at a temperature higher than the decomposition temperatures of the compound (a) and (b) to nickel particles and simultaneously deposit a nickel-containing spinel layer, or further a metal oxide layer on the spinel layer.

Abstract: In an ink jet head including a substrate having a opening for a pressure chamber, a section of the opening is gradually increased from a front surface of the substrate to an intermediate level of the substrate and is gradually decreased from the intermediate level of the substrate to a back surface of the substrate. The opening at the front surface of the substrate serves as a nozzle.

Abstract: Nickel composite particles having a layer of a nickel-containing spinel on at least a part of the surface of nickel particles, or nickel composite particles having an oxide layer of metals other than nickel on at least a part of the surface of nickel particles and a layer of a nickel-containing spinel at an interface between the nickel particles and the metal oxide layer. The nickel composite particles are produced by forming fine liquid droplets from a solution containing (a) at least one thermally decomposable nickel compound and (b) at least one thermally decomposable metal compound capable of forming a spinel together with nickel; and heating the liquid droplets at a temperature higher than the decomposition temperatures of the compound (a) and (b) to nickel particles and simultaneously deposit a nickel-containing spinel layer, or further a metal oxide layer on the spinel layer.

Abstract: Nickel composite particles having a layer of a nickel-containing spinel on at least a part of the surface of nickel particles, or nickel composite particles having an oxide layer of a metal other than nickel on at least a part of the surface of nickel particles and a layer of a nickel-containing spinel at an interface between the nickel particles and the metal oxide layer. The nickel composite particles are produced by forming fine liquid droplets from a solution containing (a) at least one thermally decomposable nickel compound and (b) at least one thermally decomposable metal compound capable of forming a spinel together with nickel; and heating the liquid droplets at a temperature higher than the decomposition temperatures of compounds (a) and (b) to form nickel particles and simultaneously deposit a nickel-containing spinel layer, or further, a metal oxide layer on the spinel layer.

Abstract: A ferrite fine powder having a mean particle size of 0.1 to 30 &mgr;m and consisting of spherical single-crystal particles. The ferrite fine powder has superior physical properties and excellent magnetic properties desirable for the use as a raw material for a dust core of coils, transformers, etc. The powder is prepared by forming a solution or suspension containing a compound or compounds of at least one of the metals composing ferrite into fine droplets, and thermally decomposing the droplets at elevated temperatures.

Abstract: A method for preparing a highly crystallized metal powder, comprising: supplying at least one heat-decomposable metal compound powder into a reaction vessel using a carrier gas; and forming a metal powder by heating the metal compound powder in a state in which the metal compound powder is dispersed in a gas phase at a concentration of no more than 10 g/liter, at a temperature that is over the decomposition temperature of the metal compound powder and at least (Tm −200)° C. when the melting point of the metal contained in the metal compound powder is Tm° C. The method provides a high-purity, high-density, highly dispersible, fine, highly crystallized metal powder consisting of spherical particles of uniform size, which is suited to use in thick film pastes, and particularly conductor pastes and the like used in the preparation of multilayer ceramic electronic parts.

Abstract: Nozzles for jetting ink droplets and ink chambers connected to the respective nozzles are formed in a substrate. Ink filling the ink chambers is pressurized. Ink pools are also formed adjacent to the ink chambers through partition walls, for supplying ink to the ink chambers. The partition wall makes a predetermined angle with respect to a surface of the substrate. The ink pools are formed adjacent to the ink chambers through thin partition walls. Further, the nozzles are arranged in a line and row matrix and the line of nozzles or the side of ink pools makes a constant angle with respect to a printing direction.

Abstract: In an ink jet head including a substrate having a opening for a pressure chamber, a section of the opening is gradually increased from a front surface of the substrate to an intermediate level of the substrate and is gradually decreased from the intermediate level of the substrate to a back surface of the substrate. The opening at the front surface of the substrate serves as a nozzle.

Abstract: A metal powder having a vitreous thin layer on at least a part of the surface thereof wherein the amount of the vitreous thin layer is preferably 0.01 to 50% by weight based on the metal powder without the vitreous thin layer. The metal powder is prepared by a process comprising the steps of: bringing a solution comprising a heat-decomposable metal compound to fine droplets; and heating the droplets to a temperature above the decomposition temperature of the metal compound, wherein a precursor of an oxide, heat-decomposable to produce a vitreous material which, together with the metal, does not form a solid solution, is added to the solution and the vitreous material is deposited, upon the heating, in the vicinity of the surface of the metal powder. The powder is useful for the preparation of a thick film paste used in a multilayer ceramic electronic component or substrate, since it has an excellent oxidation resistance during storage, in a conductor paste, and during firing of the paste.

Abstract: A nickel powder having at at least part of the surface thereof a layer of a composite oxide represented by the formula: A.sub.x B.sub.y O.sub.(x+2y), wherein A stands for at least one element selected from the group consisting of Ca, Sr and Ba; B stands for at least one element selected from the group consisting of Ti and Zr; and x and y represent numbers satisfying the formula: 0.5.ltoreq.y/x.ltoreq.4.5). The nickel powder may further contains at least one selected from among boron oxide, aluminum oxide and silicon oxide. The nickel powder is produced by spray pyrolyzing a solution of thermal decomposable starting compounds of nickel and additive elements and the resultant powder is suitable for use in a thick-film conductor paste having a sintering-starting temperature close to that of ceramic layers and a shrinkage behavior close to that of a ceramic without detriment to the conductivity and electric properties thereof.

Abstract: A process for preparing a metal powder, comprising the steps of: bringing a solution comprising at least one metal salt to fine droplets; and heating the droplets to a temperature above the decomposition temperature of the metal salt, wherein at least one compound which is heat-decomposable to produce a metal, a semimetal or an oxide of the metal or semimetal capable of remaining unmelted upon heating at the heat temperature is added to the solution and at least one selected from the group consisting of the metal, semimetal and oxide is heat-segregated in the vicinity of the surface of the metal powder. The resultant metal powder has a uniform particle size and good dispersibility without fusing or aggregation and is useful for the preparation of thick film pastes used in electronic circuits or components.

Abstract: A nickel powder having a composite oxide layer comprising lanthanum and nickel and, optionally an oxide of chromium, on at least a part of the surface thereof. The nickel powder is produced by a process comprising the steps of: bringing a solution comprising at least one heat-decomposable nickel compound and at least one heat-decomposable lanthanum compound and, optionally, at least one heat-decomposable chromium compound, to fine droplets; and heating the droplets at a temperature above the decomposition temperatures of these compounds to prepare a nickel powder and, at the same time, to deposit a composite oxide layer comprising lanthanum and nickel and, when present, chromium oxide, in the vicinity of the surface of the nickel powder.

Abstract: A crystallized glass for a substrate of an information-recording disk, which has been obtained by melting a glass forming material consisting essentially of, in wt. % as oxide, 55 to 85% of SiO.sub.2, 5 to 20% of Li.sub.2 O, 0 to 10% of K.sub.2 O+Na.sub.2 O, 0 to 10% of MgO, 0 to 20% of CaO, 0 to 10% of SrO, 0 to 10% of BaO, 0 to 10% of ZnO, 0 to 10% of Al.sub.2 O.sub.3, 0 to 15% of B.sub.2 O.sub.3, 0 to 6% of P.sub.2 O.sub.5, 0 to 3% of TiO.sub.2, 0 to 3% of ZrO.sub.2, 0 to 3% of SnO.sub.2 and 0 to 1% of As.sub.2 O.sub.3 +Sb.sub.2 O.sub.3, 0.1 to 10 wt. % of F and 0.1 to 20 wt. % of Cl, molding, vitrifying and crystallizing the material, and which contains at least 0.05% by weight of chlorine after crystallization. The glass forming material may further contain 0 to 10% of Fe.sub.2 O.sub.3, 0 to 10% of Cr.sub.2 O.sub.3, 0 to 10% of NiO, 0 to 10% of V.sub.2 O.sub.5, 0 to 10% of CuO, 0 to 10% of MnO.sub.2, 0 to 10% of MoO.sub.3, the total of Fe.sub.2 O.sub.3 +Cr.sub.2 O.sub.3 +NiO+V.sub.2 O.sub.5 +CuO+MnO.sub.

Abstract: An oxidation-resistant palladium powder containing one or more alkaline earth metal elements in a total amount of at least 0.005% by weight relative to Pd. The palladium powder is useful as a conductive component of a thick-film conductive paste and the resultant conductive paste can provide internal electrodes to a multilayered ceramic capacitor with minimized structural defects such as cracks or delamination. The palladium powder is produced by spraying a palladium salt solution containing one or more alkaline earth metal elements to form droplets and heating the droplets to a temperature of at least 1000.degree. C. The preferred amount of the alkaline earth metal elements in the Pd powder is from 0.005 to 0.1% by weight relative to Pd and the preferred alkaline earth metal elements are one or more elements selected from the group consisting of Mg, Ca, Sr and Ba.