naa a22 4500 510767516 CHVBK 20180411083201.0 cr unu---uuuuu 180411e20131201xx s 000 0 eng 10.1007/s12043-013-0625-1 doi (NATIONALLICENCE)springer-10.1007/s12043-013-0625-1 Phonon dispersions in graphene sheet and single-walled carbon nanotubes [Elektronische Daten] [DINESH KUMAR, VEENA VERMA, H BHATTI, KEYA DHARAMVIR] In the present research paper, phonons in graphene sheet have been calculated by constructing a dynamical matrix using the force constants derived from the second-generation reactive empirical bond order potential by Brenner and co-workers. Our results are comparable to inelastic X-ray scattering as well as first principle calculations. At Γ point, for graphene, the optical modes (degenerate) lie near 1685cm − 1. The frequency regimes are easily distinguishable. The low-frequency (ω→ 0) modes are derived from acoustic branches of the sheet. The radial modes can be identified with ω→ 584cm − 1. High-frequency regime is above 1200cm − 1 (i.e. ZO mode) and consists of TO and LO modes. The phonons in a nanotube can be derived from zone folding method using phonons of a single layer of the hexagonal sheet. The present work aims to explore the agreement between theory and experiment. A better knowledge of the phonon dispersion of graphene is highly desirable to model and understand the properties of carbon nanotubes. The development and production of carbon nanotubes (CNTs) for possible applications need reliable and quick analytical characterization. Our results may serve as an accurate tool for the spectroscopic determination of the tube radii and chiralities. Indian Academy of Sciences, 2013 Graphene nationallicence carbon nanotubes nationallicence force constants and dynamical matrix nationallicence phonon dispersions nationallicence vibrational density of states nationallicence specific heat nationallicence radial breathing mode nationallicence KUMAR DINESH Department of Physics, Punjabi University, 147002, Patiala, India aut VERMA VEENA Department of Physics, Govt. Shivalik College, Naya Nangal District, 140 126, Ropar, India aut BHATTI H. Department of Physics, Punjabi University, 147002, Patiala, India aut DHARAMVIR KEYA Centre for Advance Study in Physics, Panjab University, 160 014, Chandigarh, India aut Pramana Springer India 81/6(2013-12-01), 1021-1035 0304-4289 81:6<1021 2013 81 12043 https://doi.org/10.1007/s12043-013-0625-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12043-013-0625-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- KUMAR DINESH Department of Physics, Punjabi University, 147002, Patiala, India aut NATIONALLICENCE 700 1- VERMA VEENA Department of Physics, Govt. Shivalik College, Naya Nangal District, 140 126, Ropar, India aut NATIONALLICENCE 700 1- BHATTI H. Department of Physics, Punjabi University, 147002, Patiala, India aut NATIONALLICENCE 700 1- DHARAMVIR KEYA Centre for Advance Study in Physics, Panjab University, 160 014, Chandigarh, India aut NATIONALLICENCE 773 0- Pramana Springer India 81/6(2013-12-01), 1021-1035 0304-4289 81:6<1021 2013 81 12043 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer