Abstract: Nickel powder includes, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 times the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 times the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto an internal or external electrode for electronic parts.

Abstract: Nickel powder includes, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 times the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 times the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto an internal or external electrode for electronic parts.

Abstract: The nickel powder is characterized in that the rate of the nickel particles whose particle size is not less than 1.2 time the average particle size as determined by the observation with an SEM is not more than 5% of the total number of nickel particles and that the rate of nickel particles whose particle size is not more than 0.8 time the average particle size is not more than 5% of the total number of nickel particles. The nickel powder is produced by bringing a slurry, containing nickel hydroxide, which is prepared by adding an aqueous solution of a nickel salt to an aqueous solution of an alkali metal hydroxide, into contact with a hydrazine reducing agent under the temperature conditions of not less than 55° C. to reduce the nickel hydroxide.

Abstract: Nickel powder comprises, on the basis of the total number of particles, not less than 10% of particles whose particle size is not less than 1.2 time the average particle size, as determined by the SEM observation; and not less than 10% of particles whose particle size is not more than 0.8 time the average particle size, as determined by the SEM observation. The nickel powder can be prepared by, for instance, precipitating nickel particles from an aqueous solution containing a nickel salt and a hydrazine reducing agent, without forming any hydroxide of nickel as an intermediate. A conductive paste containing the nickel powder can be applied onto the positions on which an internal or external electrode for electronic parts and then baking the coated paste to give an electrode.

Abstract: The composite nickel fine powder includes surface-oxidized nickel fine particles and at least one member selected from the group consisting of oxides and complex oxides of at least one metal element having an atomic number ranging from 12 to 56 or 82 and belonging to Group 2 to 14 of the Periodic Table on the surface of the surface-oxidized nickel fine particles.

Abstract: The present invention relates to nickel powder characterized in that the rate of the nickel particles whose particle size is not less than 1.2 time the average particle size as determined by the observation with an SEM is not more than 5% of the total number of nickel particles, that the rate of nickel particles whose particle size is not more than 0.8 time the average particle size is not more than 5% of the total number of nickel particles and that the tap density of the nickel powder is not less than 2.5 g/cm3, as well as a conductive paste for use in making a multilayer ceramic capacitor. The nickel powder of the present invention has a narrow particle size distribution and an excellent packing ability in a conductive paste and is particularly suitably used for forming a thin and uniform inner electrode for a multilayer ceramic capacitor, without being accompanied by the formation of any crack and/or the generation of any delamination.

Abstract: Surface-modified nickel fine powder herein disclosed is characterized in that the surface of metal nickel fine particles is modified with a phosphate compound, a phosphite compound or a hypophosphite compound. The surface-modified nickel fine powder has a sharp heat shrinkage-initiating temperature shifted to not less than 900° C., can thus be quite suitable for use in the manufacture of an internal electrode for multi-layered capacitors and can accordingly inhibit any generation of delamination and crack-formation during the production of a high capacitance multi-layered ceramic capacitor.

Abstract: The composite nickel fine powder includes surface-oxidized nickel fine particles and at least one member selected from the group consisting of oxides and complex oxides of at least one metal element having an atomic number ranging from 12 to 56 or 82 and belonging to Group 2 to 14 of the Periodic Table on the surface of the surface-oxidized nickel fine particles.

Abstract: Composite nickel fine powder comprises metal nickel fine particles, at least one member attached to the surface of the fine particles and selected from the group consisting of oxides and double oxides containing at least one metal element selected from the group consisting of the Groups 2 to 14 of the Periodic Table and whose atomic number falls within the range of from 12 to 82, and a saturated or unsaturated fatty acid supported on the surface of the nickel fine particles provided thereon with the oxide and/or double oxide attached thereto. The composite nickel fine powder is excellent in resistance to heat shrinkage, has a high tap density, and has characteristic properties suitable for use as a material for making a conductive paste.

Abstract: Nickel fine powder comprises nickel and phosphorus dispersed in the nickel in an amount ranging from 0.01 to 2% by weight on the basis of the weight of the nickel and having a particle size of not more than 0.5 &mgr;m. The nickel fine powder can be prepared by a method comprising the step of reducing nickel hydroxide in the presence of phosphorus ions in such an amount that the molar ratio of phosphorus ions to nickel ions falls within the range of from 0.01 to 2.

Abstract: A nickel fine powder includes 0.02 to 1.0% by weight of magnesium and/or 0.02 to 0.1% by weight of calcium dispersed in the nickel. A method for preparing the nickel fine powder includes the steps of forming nickel hydroxide by mixing an aqueous solution containing a magnesium salt and/or a calcium salt and a nickel salt with an aqueous solution of sodium hydroxide and then reducing the hydroxide with a hydrazine reducing agent. The nickel fine powder has thermal shrinkage characteristics very close to those observed for ceramic substrates and is accordingly suitable as a material for producing an internal electrode for laminated ceramic condensers.

Abstract: A method for preparing nickel fine powder is herein disclosed, which comprises the steps of mixing an aqueous sodium hydroxide solution comprising, on the basis of the total weight of the sodium hydroxide present in the aqueous solution, 75 to 85% by weight of liquid caustic soda as specified in JIS K 1203 and 25 to 15% by weight, in total, of at least one of sodium hydroxide as specified in JIS K 8576 and solid caustic soda as specified in JIS K 1202, with an aqueous solution of nickel sulfate to form nickel hydroxide, then reducing the resulting nickel hydroxide with hydrazine and recovering nickel fine powder produced. The nickel fine powder prepared by the method has an average particle size of the primary particles ranging from 0.1 to 0.9 .mu.m, a D.sub.90 value of not more than 2.1 .mu.m and a tap density of not less than 3.5 g/cc.