Phonons in graphitic tubules

2019-10-07 13:29:46

spectra modes phonon tubules graphitic

责任者: Yu, J.;Kalia, R.K.;Vashishta, P. 单位: Dept. of Phys. & Astron., Louisiana State Univ., Baton Rouge, LA, USA 来源出处: Europhysics Letters(Europhys. Lett. (Switzerland)),1995/10/01,32(1):43-8 摘要: The phonon dispersion and density of states of graphitic tubules with various helicities and diameters are calculated with a tight-binding molecular-dynamics method (TBMD). Compared with graphite, phonon modes in tubules are softened by the curvature. Unique features of the graphitic tubule, with special emphasis on low-frequency modes, are discussed. The symmetry of phonon modes is analyzed, and infrared (IR) and Raman active modes are identified. It is found that not only the frequencies but also the number of IR and Raman modes depend on tubule helicity. Sound velocities in graphitic tubules are also calculated as functions of tubule helicity and diameter 关键词: carbon;infrared spectra;molecular dynamics method;nanostructured materials;phonon dispersion relations;phonon spectra;Raman spectra;soft modes;tight-binding calculations;graphitic tubules;phonon dispersion;phonon states density;tight binding molecular dynamics method;phonon softening;phonon modes symmetry;infrared spectra;Raman spectra;tubules helicity;C