High‐pressure optical study of small‐diameter chirality‐enriched single‐wall carbon nanotubes
High‐pressure optical study of small‐diameter chirality‐enriched single‐wall carbon nanotubes
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DOI：
10.1002/pssb.201600358
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发表时间：
2016-12
期刊：
影响因子：
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通讯作者：
M. Krottenmüller;W. Gao;B. Anis;J. Kono;C. Kuntscher
中科院分区：
文献类型：
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作者：
M. Krottenmüller;W. Gao;B. Anis;J. Kono;C. Kuntscher
我们通过高压下的光学吸收光谱研究了小直径单壁碳纳米管（SWCNT）薄膜的机械稳定性。所研究的样品富含（6，5）SWCNT，以便即使在高压下也观察到尖锐的光学转变。我们在研究的频率范围内观察到两个定义明确的吸收带，这两个吸收带都随着压力的增加而红移。压力引起的一个吸收带的红移率在8 GPa下发生了显着变化，我们将其解释为纳米管横截面从圆形到椭圆形的结构相变。通过将数据与平均直径为1.4 nm的混合手性SWCNT膜的数据进行比较，我们得出结论，较小直径的SWCNT具有更高的机械稳定性，这与理论预期一致。在高达22 GPa下没有观察到（6，5）SWCNT的塌陷。
We have investigated the mechanical stability of small‐diameter single‐wall carbon nanotube (SWCNT) films via optical absorption spectroscopy under high pressure. The studied sample was enriched in (6,5) SWCNTs, in order to observe sharp optical transitions even at high pressures. We observed two well‐defined absorption bands in the studied frequency range, both of which red‐shifted with increasing pressure. The rate of the pressure‐induced red shift of one absorption band was found to change dramatically at 8 GPa, which we interpret as a structural phase transition of the nanotubes’ cross‐section from circular to oval. By comparing the data with that for a film of mixed‐chirality SWCNTs with an average diameter of 1.4 nm, we conclude that smaller‐diameter SWCNTs have higher mechanical stability, which is consistent with theoretical expectations. No collapse of (6,5) SWCNTs was observed up to 22 GPa.