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).