Potential Effect of Multi-Walled Carbon Nanotube Irradiated with Highly Charged Ions

We evaluated structural modification of multi-walled carbon nanotubes (MWCNTs) before and after irradiation with highly charged ions (HCIs) produced by electron beam ion source (EBIS). Interaction of HCI with surface results in emission of many electrons and ions and modifies the structure of surface layers over nm region. We used transmission electron microscopy (TEM) as evaluation method of structural change. MWCNTs were prepared by chemical vapor deposition (CVD). TEM images of MWCNTs irradiated with Ar14+ exhibit uneven surfaces at the fluence of 6×1013 ions/cm2. This kind of structural modification is not seen in the case of Ar+ and electron irradiations, therefore the uneven surface is considered to be caused by the potential energy of HCIs, that is potential sputtering occurred on the surfaces of MWCNTs.