Enhanced critical pressure for buckling of carbon nanotubes due to an inserted linear carbon chain

Recent findings of linear carbon-atom chains (C-chains) inside carbon nanotubes have stimulated considerable interest. In this work, molecular dynamics (MD) simulation and an elastic string-elastic shell model is adopted to study radial pressure-induced buckling of single-walled carbon nanotubes (SWCNT) filled with a C-chain. The continuum model predicts that the C-chain increases critical buckling pressure considerably (about 40%-160%) for SWCNTs of diameters ranging from 0.68 to 0.72 nm, in reasonable quantitative agreement with the prediction of MD simulation. In particular, the MD simulation confirms that the originally circular cross section of filled SWNTs becomes elliptical after buckling, as predicted by the continuum model