孤立悬浮单壁碳纳米管的温度依赖性拉曼光谱。

Temperature dependent Raman spectra of isolated suspended single-walled carbon nanotubes.

作者信息

Zhang Xiao, Yang Feng, Zhao Duan, Cai Le, Luan Pingshan, Zhang Qiang, Zhou Wenbin, Zhang Nan, Fan QingXia, Wang Yanchun, Liu Huaping, Zhou Weiya, Xie Sishen

机构信息

Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.

出版信息

Nanoscale. 2014 Apr 21;6(8):3949-53. doi: 10.1039/c3nr04405j.

DOI:10.1039/c3nr04405j

PMID:24202030

Abstract

Ultralong isolated single-walled carbon nanotubes (SWCNTs) were synthesized on a SiO₂/Mo mesh to fabricate long individual suspended SWCNT samples. We detected a delicately temperature dependent Raman RBM, G and G' band frequency shift and linewidth increase of these SWCNTs in the range of 240-600 K. Softening of force constants induced redshift and the mechanism of corresponding spectra linewidth evolution with temperature was analysed and compared with previously reported theories and experimental results. Temperature coefficient differences between G(-) and G(+) were not observed, but the linewidth broadening tendency differences of G(-) and G(+) are obvious. In addition, temperature-dependent G' band evolution, including both frequency red-shifting and FWHM increase has been reported here first. These results will facilitate understanding of the second order Raman scattering process in SWCNTs. Different temperature coefficients measured on suspended and supported parts of the same SWCNT verifies the substrate's influence.

摘要

超长孤立单壁碳纳米管（SWCNT）在SiO₂/Mo网格上合成，以制备长的单个悬浮SWCNT样品。我们在240 - 600 K范围内检测到这些SWCNT的拉曼RBM、G和G'带频率随温度微妙变化以及线宽增加。分析了力常数软化引起的红移以及相应光谱线宽随温度的演化机制，并与先前报道的理论和实验结果进行了比较。未观察到G(-)和G(+)之间的温度系数差异，但G(-)和G(+)的线宽展宽趋势差异明显。此外，首次报道了温度依赖的G'带演化，包括频率红移和半高宽增加。这些结果将有助于理解SWCNT中的二阶拉曼散射过程。在同一SWCNT的悬浮部分和支撑部分测量的不同温度系数验证了衬底的影响。