Load-driven morphological evolution in covalently bridged multiwalled carbon nanotubes

Under pure bending or compression multiwalled carbon nanotubes (MWCNTs) with interwall covalent bridges exhibit evolving morphologies, ranging from uniform deformation, wavelike rippling, to Yoshimura (diamond-shaped) pattern. Using large-scale coarse-grained simulations, we map out the morphological phase diagram in the space of applied strain and interwall bridging density and find that the three deformation phases are separated by two linear transition boundaries. Our energetics analyses reveal that the relative significance of the in-plane deformation energy and the interwall bridging energy determines the shape space of MWCNTs. The multiple morphological transformations open pathways for mechanically tuning the electronic and magnetic properties of MWCNTs.