| 摘要 |
PROBLEM TO BE SOLVED: To impart useful sintering characteristics and excellent oxidation resistance to a nickel powder useful as an inner electrode of a laminated ceramic capacitor by preparing the nickel powder having a specified metal nickel content measured by X-ray photoelectron spectroscopic analysis. SOLUTION: A metal nickel having about 5 to 20 mm particle size and about >=99.9% purity is reacted with chlorine gas in the temp. range of about 900 to 1,100 deg.C to produce nickel chloride gas. The produced nickel chloride gas is brought into contact and reacted with hydrogen gas in the temp. range of about 900 to 1,100 deg.C to produce a metal nickel powder. The metal nickel powder is cooled to obtain the nickel powder having a desired particle size. The powder is heat-treated at a temp. of about 200 to 400 deg.C in an oxidative atmosphere for 1 min to 10 hours to form film oxide films. Thereby, the obtd. nickel powder has 0 to 10 atomic metal nickel content measured by X-ray photoelectron spectroscopic analysis, and has >=2 nm thickness of the oxide film.
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