Spectroscopic characterization of Stone-Wales defects in nanotubes

Abstract

We combined resonant photoabsorption and vibration spectroscopy with scanning tunneling microscopy ͑STM͒ to unambiguously identify the presence of Stone-Wales ͑SW͒ defects in carbon and boron nitride nanotubes. Based on extensive time-dependent ab initio density functional calculations, we propose to resonantly photoexcite SW defects in the infrared and ultraviolet regime as a means of their identification. Onset of nonradiative decay to a local defect vibration with a frequency of 1962 cm Ϫ1 serves as a fingerprint of such defects in carbon nanotubes. The bias dependence of the STM images shows distinct features associated with the presence of SW defects.

Molecular Dynamics Simulation Study on the Mechanical Properties and Fracture Behavior of Single-Wall Carbon Nanotubes

“…In 1995 Ebbensen & Takada (Ebbesen & Takada, 1995) got an experimental evidence of topological defects such as Stone-Wales defects in CNTs. Miyamoto et al (Miyamoto et al, 2004) made an experimental identification of SW defects in CNT samples. Thus the experiments established the facts that the lower values of Young's modulus and tensile strength of CNTs originated because of the presence of defects in them, in particular the SW defects.…”

Molar Binding Energy of Zigzag and Armchair Single-Walled Boron Nitride Nanotubes

“…The dipole appears to be more favorable in spite of its homoelemental B−B and N−N bonds. The resonant photoabsorption and vibration spectroscopy combined with scanning tunneling microscopy unambiguously identify the presence of Stone-Wales defects in BN nanotubes [97]. Based on extensive timedependent DFT calculations, it was proposed to resonantly photoexcite such defects in the IR and UV regimes as a means of their identification.…”

Stability of carbon nanotubes under electron irradiation: Role of tube diameter and chirality

“…23,24 These topological defects representing a pentagon-heptagon pair are metastable, at least at low temperatures, and can be detected by spectroscopic techniques. 25 At high initial energies the recoil atom leaves its position and travels to infinity or it is adsorbed on the tube surface outside the immediate recombination radius, as depicted in Fig. 2͑b͒.…”