Comparative micro-Raman spectroscopy study of tellurium-filled double-walled carbon nanotubes

Abstract

Tellurium-filled double-walled carbon nanotubes (Te@DWNTs) have been studied by Raman spectroscopy in the temperature interval from 300to700K employing 785nm excitation wavelength, and their spectra have been compared to those of pristine double-walled carbon nanotubes (DWNTs). The DWNTs were synthesized by catalytic chemical vapor deposition. Assignment of the radial breathing modes and the tangential modes was done based on the one dimensional electronic energy band structure of carbon nanotubes. The tangential mode components of Te@DWNT are downshifted compared to those of pristine DWNT consistent with the proposed weakening of the carbon-carbon bond due to the introduced van der Waals interaction of the Te atoms with the DWNT. It was established that Te@DWNT can be unambiguously identified by the 30% temperature coefficient decrease of the G′-band position.