低能甲烷和氢气混合离子束诱导产生石墨纳米晶包覆多壁碳纳米管的复合结构

Nanographite (NG) deposits were formed on multiwalled carbon nanotubes (MWCNTs) lying on a singlecrystalsilicon plane by irradiating them with an 80eV ion beam perpendicular to the plane. The ion beam was produced using a methane and hydrogen mixture (1∶5) at 700℃. Electron microscopy indicates that there is an angle in the range 45° -90° between the (0002) planes of the formed NG particles and the axis of the MWCNTs. The MWCNTs retained their inner hollow structure. The formation of the NGs can be ascribed to the high temperature decomposition and deposition of methane, and the observation of specific angles (45°-90° ) between the (0002) planes of the NGs and the MWCNT axis may be attributed to the selective etching, or removal, by the hydrogen ions of NG nuclei with 0°-45° between their (0002) planes and the MWCNT axis.