Tube-Length Dependence on Theoretical Raman Spectra of Single-Walled BC3 Nanotubes and Bundle Size Effect

Abstract

Polarized Raman spectra of single-walled BC3 nanotubes (SBCNTs) are calculated as a function of their diameter, chirality, length, and bundle size using a classical force field combined with the bond-polarizability model. For isolated infinite tubes, we give a mathematical model to estimate their diameter from their Raman spectra. The tangential modes are sensitive to the tube chirality. The length shortening of the tube below ∼50 nm leads to the appearance of several additional Raman lines in the regions of breathing modes and tangential modes. For SBCNT bundles, the position of the radial breathing mode is significantly upshifted with respect to its position in isolated SBCNTs, and a specific bundle breathing-like mode is observed below 300 cm–1.