Abstract Submitted to the    NANOTUBE'04 Conference:

Similar to the conventional semiconductor technology, beams of energetic particles can be used to modify the structure and properties of carbon nanotubes in a controllable manner. In particular, 50 keV Ga ion irradiation of multi-walled nanotubes (MWNTs) gave rise to the formation of highly ordered pillbox-like nanocompartments in the tube interior and to changes in the electronic structure of irradiated MWNTs [1]. Ar ion beams have been employed to enhance the field emission from MWNTs [2] and to make MWNT-based quantum dots [3] as well as single-electron inverters [4].

At the same time, despite substantial experimental progress, there is still very little understanding of irradiation-induced phenomena in carbon nanotubes. Many traditional concepts in ion-solid interaction theory do not work at the nano-scale at all or they require substantial modifications.

In our previous works [5], we addressed effects of irradiation on single-walled nanotubes which have a simpler atomic structure than MWNTs. Now, using atomistic computer simulations, we systematically study irradiation-mediated phenomena in MWNTs. By modeling impacts of energetic ions, we examine production of defects in MWNTs and estimate the ranges of ions with different characteristics.

Finally, due to the growing interest in solid-state quantum computing [6], we study how MWNTs can be used for spatially-selective ion implantation into the material. We demonstrate that MWNT can effectively channel ions with certain energies through MWNT empty cores. We put forward suggestions for making a MWNT-based nano-aperture device which can potentially be used for producing a beam just a couple of nm in cross-section, steering the beam and thus irradiating pre-selected areas of the sample.

[1] B.Q. Wei et al. Appl. Phys. Lett. 83 (2003) 3581.
[2] D.-H. Kim et al. Chem. Phys. Lett. 378 (2003) 232.
[3] M. Suzuki et al. Appl. Phys. Lett. 81 (2002) 2273.
[4] K. Ishibashi et al. Appl. Phys. Lett. 82 (2003) 3307.
[5] A.V. Krasheninnikov et al. Phys. Rev. B 66 (2002) 245403; ibid 65 (2002) 165423; ibid 63 (2001) 245405, ibid 69 (2004) 073402.
[6] B.E. Kane, Nature 393 (1998) 133.