Synthesis and characterization of Cu nanotubes and nanothreads by electrical arc evaporation

Abstract

We report the formation and characterization of copper nanostructures, nanotubules and nanothreads, which were obtained by electrical arc evaporation of Cu electrodes under varied conditions of He ambience. Electrical arc evaporation was done with ∼10 V and (∼50-100 A) DC current. The current was used in a pulse mode. The evaporated material was condensed on a formvarcoated Cu grid mounted on a liquid N 2-cooled specimen holder. Transmission electron microscopy was employed to characterize the condensed materials. These investigations revealed that the condensed materials consisted of the mentioned nanostructures. Nanotubes and nanothreads are formed for a He pressure in the chamber corresponding to ∼140 and ∼500 torr, respectively. Extensive electron microscopic investigations showed that the diameter of the nanotubes varied from ∼5 nm to ∼50 nm and their length from 2 μm to 3 μm.