Surface analysis of ultrafine copper powders

Ultrafine copper powders produced by the inert gas evaporation method (particle diameter 10 - 20 nm) were examined by different surface analytical methods. After a contact of the powders with the surrounding atmosphere the following surface structure is formed on the copper surface. A built up of a thin Cu sub 2 O layer takes place, but no generation of CuO. Additionally, the surface is covered with adsorbed oxygen and CO.