Obtaining and Oxidation of Nanocrystallite Powders of Nickel-Copper System
V. M. PUGACHEV1, YU. A. ZAKHAROV1,2, O. V. VASILYEVA1, YU. V. KARPUSHKINA1, V. G. DODONOV1
1Kemerovo State University, Ul. Krasnaya 6, Kemerovo 650043 (Russia)
2Institute of Coal Chemistry and Material Science, Siberian Branch of the Russian Academy of Sciences, Sovetskiy Pr.18, Kemerovo 650000 (Russia)
Keywords: phase diagram, phase composition, solid solutions, copper-nickel system, lattice parameters, nanometer-sized metals, metal oxides
Abstract
Nanosized powders of nickel-copper system were obtained by reduction of metal salts with hydrazine in strongly alkaline solutions. The particle size was studied using X-ray diffraction methods including small-angle scattering. The size of crystallites and nanoparticles, phase composition, lattice parameters of two fine metal phases formed in the system (solid solutions) were determined; oxidation products were studied. It was established that the size of bimetal nanoparticles within a broad range of compositions is substantially smaller in comparison with pure components (nickel and copper) obtained under the same conditions. It was shown that the ability of particles to get oxidized increases with a decrease in nickel content. The samples containing 90 % copper and obtained in the atmosphere of nitrogen are easily oxidized by atmospheric oxygen to CuO. In the case of preliminary etching with hydrochloric acid, these samples are oxidized to Cu2O.
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