等离子体诱导碳纳米管到纳米金刚石的相变

采用氢等离子体，实现了碳纳米管向金刚石的结构相变，并实现了金刚石的高密度成核，有效成核密度可达10\+\{11\}／cm\+2以上，处于目前金刚石成核密度的最高行列，为制备优质的金刚石薄膜提供了保证.高分辨透射电镜、x射线衍射和拉曼光谱都证实了金刚石的形成.同时，对纳米金刚石晶粒的生成机理进行了初步探讨. 关键词： 等离子体 碳纳米管 纳米金刚石 结构相变

Plasma-induced transformation of carbon nanotubes to nanocrystalline diamond

Structural phase transformation from multiwalled carbon nanotubes to nanocrystalline diamond by hydrogen plasma post-treatment was carried out. Ultrahigh equivalent diamond nucleation density above 10~(11) nuclei/cm~2 was easily obtained. The diamond formation and growth mechanism was proposed to be the consequence of the formation of sp~3 bonded amorphous carbon clusters. The hydrogen chemisorption on curved graphite network and the energy deposited on the carbon nanotubes by continuous impingement of activated molecular or atomic hydrogen are responsible for the formation of amorphous carbon matrix. The diamond nucleates and grows in the way similar to that of diamond CVD processes on amorphous carbon films. The present method of hydrogen treatment provides a controllable way for the CVD of high quality diamond films.