High Pressure Vibrational Properties of WS2 Nanotubes

Nano Lett. 2016 Feb 10;16(2):993-9. doi: 10.1021/acs.nanolett.5b03996. Epub 2016 Jan 12.

Abstract

We bring together synchrotron-based infrared and Raman spectroscopies, diamond anvil cell techniques, and an analysis of frequency shifts and lattice dynamics to unveil the vibrational properties of multiwall WS2 nanotubes under compression. While most of the vibrational modes display similar hardening trends, the Raman-active A1g breathing mode is almost twice as responsive, suggesting that the nanotube breakdown pathway under strain proceeds through this displacement. At the same time, the previously unexplored high pressure infrared response provides unexpected insight into the electronic properties of the multiwall WS2 tubes. The development of the localized absorption is fit to a percolation model, indicating that the nanotubes display a modest macroscopic conductivity due to hopping from tube to tube.

Keywords: WS2 nanotubes; high pressure vibrational spectroscopies; nanoscale transition metal dichalcogenides; percolation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.