| 摘要 |
PROBLEM TO BE SOLVED: To provide a tungsten ultrafine powder which is suitable for a sintered material, an electrode material in electronic parts or the like, has an average particle diameter of 100 nm or smaller and has high purity, and to inexpensively provide an industrial production method therefor. SOLUTION: The method for producing the tungsten ultrafine powder which has the average particle diameter of 100 nm or smaller and a geometrical standard deviation of the particle diameter in an amount of 1.35 or less comprises the steps of: vaporizing a tungsten compound such as WO<SB>3</SB>with thermal plasma in a reductive atmosphere containing an inert gas and hydrogen gas; and condensing the obtained tungsten vapor to form the fine powder. It is preferable to form a thin film of tungsten oxide on the surface of the obtained tungsten ultrafine powder by gradually oxidizing the ultrafine powder in an inert gas atmosphere containing oxygen. COPYRIGHT: (C)2007,JPO&INPIT
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