Raman spectra of carbon nanowires made of single walled carbon nanotubes encasing polyynes

Abstract

In this work, the Raman spectra of LCCs encapsulated single-walled carbon nanotubes (SWCNTs) are calculated using the spectral moment’s method. To derive the optimum configurations of the linear carbon chains inside nanotubes, the minimum energy calculations using a convenient Lennard-Jones expression of the van der Waals intermolecular potential is devoted. The optimized structures show that the minima correspond to nanotubes configurations with diameter close to 0.68nm. The influence of the nanotube diameter and chirality are investigated. We also address the important question of the effect of filling degree using the frequency of Raman active modes. These predictions are useful to interpret the experimental data.