On the roles of multilayered metal catalysts in the synthesis of high-quality single-walled carbon nanotubes

In this paper, high quality single-walled carbon nanotubes (SWNTs) were synthesized by multilayered metal catalysts on silicon or silicon oxide substrate using thermal chemical vapor deposition method. The roles of multilayered metal catalyst were investigated by systematically varying the combinations of multilayered structure. Scanning electron microscopy, Atomic force microscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy were used to examine the evolution of the morphology and the oxidation state of each constituent of the multilayered structure in the thermal processes and their roles in controlling the formation of SWNTs.