Wall thikness effects on the infrared spectra of multi-walled carbon nanotubes

In this theoretical work, we investigate the infrared vibrational features of multi-walled carbon nanotubes (MCNTs). We calculate the polarized infrared spectra of multi-walled carbon nanotubes using the spectral moment's method. This original approach allows us to consider MCNTs with a large number of walls. We discuss the evolution of the low, intermediate and high wavenumber regions of these spectra as a function of the inner diameter and the size of MCNTs. Both the XX and ZZ polarisations are considered. Our results provide benchmark theoretical data for understanding the experimental infrared spectra of MCNTs.