• carbon:nickel nanocomposites;
  • Raman spectroscopy;
  • SWCNT diameter control;
  • SWCNT growth


Thumbnail image of graphical abstract

Carbon:nickel (C:Ni) nanocomposite thin films deposited by ion beam co-sputtering were used for catalytic chemical vapor deposition (CVD) growth of single-walled carbon nanotubes (SWCNTs). The SWCNTs were characterized by scanning electron microscopy and Raman spectroscopy. The approach allows a precise and reproducible control of the catalyst diameter, while the embedding carbon matrix prevents the particles from coalescence during catalyst activation and nanotube growth. The SWCNTs obtained from Ni particles with ∼4 nm diameter have a radial breathing mode frequency distribution of 147.5 ± 32 cm−1 and a diameter distribution of 1.6 ± 0.4 nm. Small line widths of the radial breathing mode and ID/IG ratios of 0.05 indicate SWCNTs with a low defect concentration.

Left: Scheme of C:Ni nanocomposite based SWCNT synthesis. The dark contrast image regions correspond to the Ni particles. Right: Radial breathing mode Raman spectrum of a structurally highly ordered SWCNT.