Inelastic light scattering from magnetically aligned single-walled carbon nanotubes and estimate of their two-dimensional Young's modulus

Single walled carbon nanotubes (SWNT) are structures with a very high strength-to-weight ratio and this feature has recently stimulated much interest and research. We measured inelastic light scattering (low-frequency Raman scattering) in a carbon film composed of magnetically aligned single-walled nanotubes. Scattering occurs from longitudinal vibrational acoustic modes propagating along the tubes with frequencies of tens of GHz, and we describe the phenomenon via a surface elasto-optic effect, coupling the incident light to the tube thermal strains. This model also permits to estimate the two-dimensional Young's modulus of the tube walls (and thus of a single curved graphitic sheet) to be approximately 100 N m-1