电子束诱导单壁碳纳米管不稳定性的新观察

摘要

The nanoinstability of single-wall carbon nanotube（SWCNT） under electron beam irradiation is systematically investigated by in-situ transmission electron microscopie observation at room temperature.Under the same irradiation condition,it is found that with the increase of irradiation time（or electron dose）,the SWCNT whose two ends are fixed at ropes of nanotubes shrinks in its radial direction with an increasingly faster rate;the curved SWCNT is more instable than the straight one with the same diameter;the SWCNT with a free capped end but the other end fixed at a rope of nanotubes shrinks in the axial direction but almost keeps its diameter unchanged.All experimental phenomena could be well accounted for by new concepts of the nanocurvature of SWCNT and by the electron beam-induced athermal activation.%利用透射电镜在室温下对不同形态的单壁碳纳米管进行了原位电子束辐照研究.研究发现：在相同的辐照条件下随着辐照时间（或辐照剂量）的增加,两端固定的单壁碳纳米管径向收缩,且收缩速率越来越快;相同直径的轴向弯曲的单壁碳纳米管比平直的单壁碳纳米管更加不稳定;一端固定另端自由的单壁碳纳米管轴向收缩,但其直径基本不变.利用单壁碳纳米管纳米曲率效应和能量束诱导非热激活效应,对上述单壁碳纳米管的不稳定性现象进行了新的、合理的解释.