PMID- 24279772
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20150522
LR  - 20140904
IS  - 1520-5215 (Electronic)
IS  - 1089-5639 (Linking)
VI  - 118
IP  - 35
DP  - 2014 Sep 4
TI  - Effects of topological defects and diatom vacancies on characteristic vibration 
      modes and Raman intensities of zigzag single-walled carbon nanotubes.
PG  - 7235-41
LID - 10.1021/jp409209s [doi]
AB  - Defects are ubiquitous in carbon nanotubes (CNTs), despite their large formation 
      energies, and have astounding effects on their physicochemical properties. In 
      this study, we employ density-functional theory (DFT) calculations to study 
      systematically the atomic structure, stability, and characteristic vibrations of 
      pristine and defected zigzag CNTs, where the defects are of the form of 
      Stone-Wales (SW) and diatom vacancies (DV). The DFT optimized structures and the 
      phonon modes are subsequently used in conjunction with a semiempirical 
      bond-polarization model to study the nonresonant Raman spectra. For each defect 
      type, we find two CNT structures with defects parallel or oblique to the tube 
      axis. For the SW defects, the two structures have similar formation energies, 
      whereas for the DV defect, only defects parallel to the tube axis are likely to 
      exist. The results show that the defects induce a blue shift in the radial 
      breathing mode (RBM) of metallic CNTs, whereas this mode is not shifted for 
      semiconducting CNTs. However, the RBM shift or its Raman profile is not sensitive 
      to the defect type. The G-band showed more sensitivity to the defects in the form 
      of a red/blue shift in the frequency, or a partial/complete defragmentation of 
      the G bands.
FAU - Saidi, Wissam A
AU  - Saidi WA
AD  - Department of Chemical and Petroleum Engineering, University of Pittsburgh , 
      Pittsburgh, Pennsylvania 15261, United States.
LA  - eng
PT  - Journal Article
DEP - 20131218
PL  - United States
TA  - J Phys Chem A
JT  - The journal of physical chemistry. A
JID - 9890903
EDAT- 2013/11/28 06:00
MHDA- 2013/11/28 06:01
CRDT- 2013/11/28 06:00
PHST- 2013/11/28 06:00 [entrez]
PHST- 2013/11/28 06:00 [pubmed]
PHST- 2013/11/28 06:01 [medline]
AID - 10.1021/jp409209s [doi]
PST - ppublish
SO  - J Phys Chem A. 2014 Sep 4;118(35):7235-41. doi: 10.1021/jp409209s. Epub 2013 Dec 
      18.