Magneto-mechanical coupling behavior of defective single-walled carbon nanotubes

Spin-polarized density functional theory is employed to investigate the mechanical and magnetic properties of a (5, 5) carbon nanotube (CN) with a mono-vacancy. It is found that the magnetic properties of a defective CN can be modified by applied uniaxial tensile strain. The effects of uniaxial strains on the magnetic properties are related to the stretched bonds in the defective CN, and the effect of a mixture of sp(2) and sp(3) hybridization on the magnetism is investigated. Furthermore, because of the strong magneto-mechanical coupling between the defective CN and metal, the mechanical properties of the defective (5, 5) CN are found to be significantly alternated by the substitution of metal atoms to its vacancy sites. Such strong coupling among magnetic moment, spin-dependent transport, and mechanical deformation in a defective CN could be beneficial in some potential applications of CNs in spintronic devices and metal matrix composites.