The Assessment Parameters of the Thickness and the Composition of the Adsorbed Layers on the Nanoparticles of Nickel, Cobalt and Titanium Powders Produced by Condensation from the Vapor Phase

The composition, the character of chemical bonding with the metal atoms and the thickness of the adsorbed layers on the surface of nanoparticles were studied. The analyses of separate layers were carried out by sputtering of the investigated surface of the sample using the accelerated argon ions with energy of 1 keV. It was revealed that, after long-term keeping in the air, the adsorbed layer mainly consists of oxygen in the state of the physical adsorption on the surface of the particles of the nanosized powders of nickel and cobalt, and that it does not take part in the oxidation of the metal atoms. Oxygen is in chemical bonding with the titanium atoms on the surface layers of nanoparticles, though the carbon atoms are not in the state of physical adsorption. In the following sublayers, the tendency of carbide formation is initially observed, but at the depth of 300Å from the physical surface, along with titanium oxide, titanium carbide is present. (author)