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

Tellurium-filled double-walled carbon nanotubes Te@DWNTs have been studied by Raman\udspectroscopy in the temperature interval from 300 to 700 K employing 785 nm excitation\udwavelength, and their spectra have been compared to those of pristine double-walled carbon\udnanotubes DWNTs. The DWNTs were synthesized by catalytic chemical vapor deposition.\udAssignment of the radial breathing modes and the tangential modes was done based on the one\uddimensional electronic energy band structure of carbon nanotubes. The tangential mode components\udof Te@DWNT are downshifted compared to those of pristine DWNT consistent with the proposed\udweakening of the carbon-carbon bond due to the introduced van der Waals interaction of the Te\udatoms with the DWNT. It was established that Te@DWNT can be unambiguously identified by the\ud30% temperature coefficient decrease of the G-band position