Wang Chengbing, Li Zhengtong, Ling San, Lei Tao, Su Jinbu
School of Materials Science & Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, People's Republic of China.
Nanotechnology. 2018 Mar 16;29(11):115602. doi: 10.1088/1361-6528/aaa63c.
We present a direct observation of the transformation of dense amorphous carbon clusters into diamond nanocrystalline under electron beam irradiation by in situ transmission electron microscopy, where the surrounding carbon matrix did not significantly change. Our findings provide clear and convincing evidence for the diamond nanocrystalline evolving from energetic amorphous carbon sites. Furthermore, graphitization of amorphous carbons usually demands a high temperature combined with high pressure. Hence, graphitization of amorphous carbons at relatively low temperatures is highly desired. Here we offer a useful method for catalyst-free graphitization of amorphous carbons by employing moderate electron beam irradiation, without external heating being applied.
我们通过原位透射电子显微镜直接观察到在电子束辐照下，致密无定形碳团簇转变为金刚石纳米晶体，而周围的碳基体没有明显变化。我们的发现为金刚石纳米晶体从高能无定形碳位点演化提供了清晰且令人信服的证据。此外，无定形碳的石墨化通常需要高温和高压。因此，非常希望在相对较低的温度下实现无定形碳的石墨化。在此，我们提供了一种有用的方法，通过适度的电子束辐照实现无定形碳的无催化剂石墨化，而无需施加外部加热。
