Structural (n, m) determination of isolated single wall carbon nanotubes by resonant Raman scattering

Abstract

We show that the Raman scattering technique can give complete structural information for onedimensional systems, such as carbon nanotubes. Resonant confocal micro-Raman spectroscopy of an ͑n, m͒ individual single-wall nanotube makes it possible to assign its chirality uniquely by measuring one radial breathing mode frequency v RBM and using the theory of resonant transitions. A unique chirality assignment can be made for both metallic and semiconducting nanotubes of diameter d t , using the parameters g 0 2.9 eV and v RBM 248͞d t. For example, the strong RBM intensity observed at 156 cm 21 for 785 nm laser excitation is assigned to the ͑13, 10͒ metallic chiral nanotube on a Si͞SiO 2 surface.

Near‐field Raman spectroscopy using a sharp metal tip

“…Raman signals of SWNTs have been studied intensively in the literature (see e.g. Duesberg et al , 2000; Jorio et al , 2001; Yu & Brus, 2001; Maultzsch et al , 2002) and signal enhancements of up to 10 12 have been reported for tubes in contact with fractal silver colloidal clusters (Kneipp et al , 2000).…”

Effects of nanomaterial physicochemical properties on in vivo toxicity

“…There at two types of CNT: single-walled (SWCNT) and multi-walled (MWCNT). SWCNT are a single tube of graphene with a diameter ranging from 0.4-3.0 nm and a length up to 1 μm [57, 58]. MWCNT are multiple layers of tubes stacking within each other with an overall diameter of 1.4-100 nm and can be up to several microns long [58].…”

Relating the physicochemical characteristics and dispersion of multiwalled carbon nanotubes in different suspension media to their oxidative reactivityin vitroand inflammationin vivo

“…Single walled CNT have typically fibre-like dimensions with diameters of 0.7-3 nm (Jorio et al 2001) and a length of up to 100 mm. Multi-walled CNT (MWCNT) consist of several layers of carbon cylinders, which increases diameter to10-200 nm (Hou et al 2003).…”