The formation of defects in carbon nanotubes under bombardment with argon ions was investigated. The π-plasmons generated in single-walled and multi-walled carbon nanotubes were examined using electron energy-loss spectroscopy. The supramolecular structure of nanotubes was step-wise modified by an argon ion beam (using a maximum irradiation dose of 360μC/cm2). The content of argon ions implanted into a nanotube structure was controlled using Auger electron spectroscopy. The effect of ion bombardment upon the π-plasmon energy and on the half-width at half-maximum of the π-plasmon spectrum was determined experimentally. An expression was derived which related the above quantities to the content of implanted argon. It was shown that the formation of defects under ion bombardment was a discontinuous process which occurred in a step-wise manner. A qualitative phenomenological interpretation was proposed for the experimentally revealed decrease in the π-plasmon energy and for the attendant broadening of the π-plasmon spectrum. The assumption was made that the microscopic mechanism of the observed phenomena was associated with narrowing of the energy π sub-bands in the electric field of charged defects generated by ions.

Investigation of the Initial Stages of Defect Formation in Carbon Nanotubes under Irradiation with Argon Ions. M.M.Brzhezinskaya, E.M.Baǐtinger, V.V.Shnitov, A.B.Smirnov: Physics of the Solid State, 2005, 47[4], 772-7