Coating of carbon nanotubes with tungsten by physical vapor deposition

A physical deposition method (PVD) to fabricate one-dimensional nanoscale composites (composite nanowires) based on a coating of carbon nanotubes (CNTs) with tungsten is presented. W vapor evaporating from a W filament is carried by H2 gas to CNTs and deposited along these CNTs. The X-ray energy dispersive spectrum (EDS) and electron energy loss spectroscopy (EELS) analyses indicated that the composite nanowires are composed of carbon and pure tungsten. The diameter of these composite nanowires is not very uniform because the W layers consist of several nanoparticles, as found from a high resolution electron microscope (HREM).