Morphology change of multi-walled carbon nanotubes with SiC coating by electron irradiation

Taguchi, Tomitsugu; Fazle Kibria, A. K. M.*; Shamoto, Shinichi  

The different behaviour between morphology changes of as-received mult-walled carbon nanotube (MWCNT) and MWCNT with SiC coating was investigated by the electron irradiation. High resolution-TEM images revealed that the deformation and bending of graphitic shells occurred in both as-received MWCNT and MWCNT with SiC coating by electron irradiation. Both of deformation and bending curvature in CNT part of MWCNT with SiC coating were smaller than those in as-received MWCNT. The electron irradiation began changing the outer and inner diameters of as-received MWCNT within 3 minutes exposure, whereas it began changing their diameters changes of MWCNT with SiC coating after 10 minutes exposure. The outer diameter of as-received MWCNT increased up to irradiation time of 9 min and then decreased rapidly. On the other hand, the outer diameter of MWCNT with SiC coating increased monotonically up to irradiation time of 50 min and then was saturated in the MWCNT with SiC coating. It might become hard to knock C atoms out from both inner and outer surfaces of CNT part by coating with SiC layer on MWCNT. These results lead that the morphology stability of MWCNT against electron irradiation is improved by coating with the SiC layer on MWCNT.