  The combination of pressure and vacancy defects are investigated to find the
ideal conditions that would create meaningful $sp^3$ interlinking without
causing severe damage to the single-walled carbon nanotubes (SWCNTs). Naturally
occurring defects fail to induce interlinking. The introduction of vacancy type
defects reduces the collapse pressure of the SWCNTs. The combination of vacancy
defects, high temperature and low pressure induces $sp^3$ without causing
severe damage to the nanotubes. Structural changes caused before and after
pressurization of the nanotubes were analyzed using Raman spectroscopy.
