Novel growth mechanism of single crystalline Cu nanorods by electron beam irradiation

Single-crystal Cu nanorods have been fabricated on carbon films by manipulating electron beam irradiation on a Cu powder charge in a transmission electron microscope (TEM). By adjusting the intensity of the electron beam, we observed lively nucleation and growth of the Cu nanorods with the TEM. Individual Cu nanorods are straight with diameters ranging from 40 to 50 nm. The length of the rods is controlled by e-beam irradiation duration, and can be extended to ∼1 μm. Selective area electron diffraction showed that the sidewalls of the Cu nanorods were associated with the (110) planes, while facets on the tips were associated with the (111) planes. We believe that the growth process is mainly controlled by high surface mobility of Cu atoms on the C surface, and surface diffusion of the Cu atoms from high surface energy planes to low surface energy planes of the Cu nanorods. (Some figures in this article are in colour only in the electronic version)