Strength analysis of a defective diamondene nanoribbon under uni-axial tension

摘要

Due to its unique sp(2)/sp(3) hybrid electron configuration, diamondene with superior physical properties diversifies the allotrope family of carbon and attracts much attention in recent year. Considering the inevitable occurrence of imperfections during its fabricating process under super high compression, influences of point vacancy or Stone-Wales (SW) defects on the tensile strength of a defective diamondene nanoribbon were examined using molecular dynamics method in the present work. Results show that a defective ribbon under tension behaves softening-to-hardening transition owing to abrupt changes of both bond length and bond angle at a critical tensile strain. Point vacancy and SW defects lead to different failure modes of the diamondene ribbon, which can be characterized by shear band originating from defects along +/- 45 degrees of stretching direction. Especially, for a ribbon with SW-1 defect (by rotating 90 degrees of a bond along stretching direction), it behaves a complicated multi-stage damage process. However, point vacancy produces two separate semi shear bands originating from the defect and later merging to be a whole shear band. After hydrogenation on both surfaces of a pristine ribbon, the softening-to-hardening transition still exists under uni-axial tension along armchair direction. However, the final fracture mode is quite different with that of the pristine counterpart. These characteristics provide guidelines on potential application of nano-devices based on diamondene.