Theoretical study of the vibrational edge modes in graphene nanoribbons
- ORNL
We investigate the phonon normal modes in hydrogen-terminated graphene nanoribbons GNRs using the second-generation reactive empirical bond order REBOII potential and density-functional theory calculations. We show that specific modes, absent in pristine graphene and localized at the GNR edges, are intrinsic signatures of the vibrational density of states of the GNRs. Three particular modes are described in details: a transverse phonon mode related to armchair GNRs, a hydrogen out-of-plane mode present in both armchair and zigzag GNRs, and the Raman radial-breathing-like mode. The good agreement between the frequencies of selected edge modes obtained using REBOII and first-principles methods shows the reliability of this empirical potential for the calculation and the assignment of phonon modes in carbon nanostructures where carbon atoms present a sp2 hybridization.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). National Center for Computational Sciences (NCCS)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1004455
- Journal Information:
- Physical Review B, Vol. 78, Issue 19; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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