Temperature dependence of Raman spectra in single-walled carbon nanotube rings

Abstract

The temperature-dependent Raman frequency shift in single-walled carbon nanotube (SWCNT) rings in the range of 80-550 K is investigated. We observe that the frequency decreases with increasing temperature for all Raman peaks of the nanotube rings. Furthermore, compared to the nanotubes with linear structure, the temperature coefficients of the radial breathing mode and G-mode frequencies of the nanotube rings are much smaller, which means the nanotube rings have more stable thermal ability. We attribute the better thermal stability to the high bending strain energy along the nanotube rings induced by the sidewall curvature. © 2008 American Institute of Physics.