Second-order overtone and combination modes in the LOLA region of acid treated double-walled carbon nanotubes

Abstract

Moderate acid treatment of double-walled carbon nanotubes (DWCNTs) has given rise to two new experimentally observed second-order double resonant Raman scattering frequencies centered at 1901 cm-1 and 1942 cm -1, in the highly dispersive LOLA region. These LOLA overtones and combination modes have been predicted by double resonance theory for two phonons associated with the K- and Γ-points, respectively. © 2006 American Institute of Physics.