High structural stability of single wall carbon nanotube under quasi-hydrostatic high pressures

Reporting high structural stability of SWNT well beyond that of sp 2 C C bonds in graphite and carbon fullerenes. In quasi-hydrostatic conditions, single wall carbon nanotubes (SWNTs) exhibit high structural stability to ∼35 GPa, well beyond the stability of sp 2 C C bonds in graphite, carbon fullerenes, benzene, and other hydrocarbons. The pressure-induced Raman changes of SWNT are completely reversible below 16 GPa, partially reversible between 16 and 35 GPa, and irreversible beyond 35 GPa where it turns into highly disordered graphite. We explain the high stability in terms of the pressure-induced structural modification to an interlinked configuration, which occurs reversibly under substantial sp 3 hybridization (∼20%) and, thus, increases the stability of sp 2 C C bonds in the SWNTs.