Resonant Raman spectroscopy on enriched 13C carbon nanotubes

✍ Scribed by Sara D. Costa; Cristiano Fantini; Ariete Righi; Alicja Bachmatiuk; Mark H. Rümmeli; Riichiro Saito; Marcos A. Pimenta

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 566 KB
• Volume: 49
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/j.carbon.2011.06.076

✦ Synopsis

Isotopically enriched single-wall carbon nanotubes with different 13 C concentrations were investigated by resonant Raman spectroscopy. Linear reductions of the Raman frequencies with an increase of 13 C concentration are observed for the different nanotube Raman modes, and the effect of the reduced mass variation of the isotope mixture on the phonon frequencies is described through a simple harmonic oscillator model. In addition to the frequency dependence, the Raman linewidths as a function of the 13 C concentration were also investigated and an expression describing this is presented. We observe an increase in the G band linewidth, as the 13 C: 12 C ratio approaches unity. Measurements with different excitation energies were performed and the frequency dispersions of the D and G 0 bands with laser energy were observed to be the same for 12 C and 13 C nanotubes, suggesting no changes in the electronic structure after isotope enrichment. Through analysis of the radial breathing modes in the Raman spectra obtained with different excitation energies, a relation between these modes frequency and the 13 C nanotubes diameter was also established.