Enhanced mechanical strength and ductility of metal-repaired defective carbon nanotubes : a density functional study

Abstract

Metal atoms are filled into the defective sites of single-walled carbon nanotube (SWCN) containing vacancy defects, resulting in a stable repaired SWCN. The tensile deformation of the repaired SWCN is investigated by spin-polarized density functional theory. Compared to the defective SWCN, the repaired CN shows significant enhancements in mechanical strength and ductility that are close to those of pristine CN. The underlying physics of these behaviors are analyzed by the structural transformation, electronic structures, and spin and charge distributions during the tensile tests. A strong magnetomechanical coupling effect is found to be responsible for the enhanced mechanical behaviors of metal-CN hybrid structures.