High pressure study of nitrogen doped carbon nanotubes using Raman spectroscopy and synchrotron X-ray diffraction

In this study, nitrogen-doped carbon nanotubes (CNx-NTs) with a 8.4% nitrogen content were investigated under high pressure using Raman spectroscopy as well as X ray diffraction (XRD) with synchrotron radiation. For comparison purpose, high pressure behaviors of carbon nanotubes (CNTs) without nitrogen were studied as well. Two phase transformations were identified in CNx-NTs, which can be assigned to tube shape change from circular to...