Abstract
We measure resonant Raman scattering of individual carbon nanotube bundles under axial strains of up to 17%. The main effect of this strain is to cause debundling of the nanotubes. The band Raman spectra of metallic and semiconducting nanotubes respond differently to strain and debundling, giving insight into the nature of the broad metallic band line shape. For metallic nanotubes, the band upshifts and becomes narrower with strain, making it appear more semiconductor-like. Surprisingly, this metal to semiconductor transition is not reversible with strain, indicating that nanotube-nanotube coupling plays a significant role in the observed band of unperturbed metallic nanotubes.
- Received 7 January 2007
DOI:https://doi.org/10.1103/PhysRevB.75.155421
©2007 American Physical Society