Formation and control of carbon nanostructures with light and sound

David Tomanek
Michigan State University, USA

Ab initio calculations and experimental data indicate that changes in the force field immediately following irradiation by light and electrons may cause important structural changes in carbon nanostructures. Exposure to specifically shaped femtosecond laser pulses may exfoliate graphite layer-by-layer [1] or convert it to diamond [2]. Photo-activated Stone-Thrower-Wales transformations may modify the morphology at the apex of carbon nanohorns during Raman spectroscopy observations [3]. Irradiation by electrons may significantly improve the structural integrity and mechanical properties of low-quality multi-wall carbon nanotubes grown by Chemical Vapor Deposition [4]. Changes in sound absorption on the sub-nanometer scale, as probed by Damping Force Spectroscopy, can be used to gain information about structural changes in the surface and subsurface region [5]. Since direct observation of atomic-scale processes following specific local perturbations is very hard by experimental means, computer simulations are a welcome alternative to gain insight into the underlying Physics.
[1] Yoshiyuki Miyamoto, Hong Zhang, and David Tomanek, Phys. Rev. Lett. 104, 208302 (2010).
[2] Ramani K. Raman, Yoshie Murooka, Chong-Yu Ruan, Teng Yang, Savas Berber, and David Tomanek, Phys. Rev. Lett. 101, 077401 (2008).
[3] M. Duchamp, R. Meunier, R. Smajda, M. Mionic, A. Magrez, J. W. Seo, L. Forro, B. Song, and D. Tomanek, J. Appl. Phys. 108, 084314 (2010).
[4] T. Fujimori, K. Urita, D. Tomanek, T. Ohba, I. Moriguchi, M. Endo, and K. Kaneko (submitted).
[5] Makoto Ashino, Roland Wiesendanger, Andrei N. Khlobystov, Savas Berber, and David Tomanek, Phys. Rev. Lett. 102, 195503 (2009).