含单空位的(10,10)碳纳米管的振动性质和拉曼谱

摘要

运用Brenner经验势计算了碳原子间力常数和具体的振动模式,在此基础上利用经验键极化模型计算了含有单空位的(10,10)碳管的非共振拉曼谱.计算结果表明,单空位造成的局域模式所对应的拉曼峰位于完整碳管的G带之外,因此,在实验上可以用这一特性来探测碳管中的单空位.同时,当单空位浓度较小时,碳管的管径几乎不发生变化,仅仅是在拉曼谱中R带上劈裂出一些新的峰,这一现象主要源自于空位带来的对称性破缺.%Using the empirical Brenner potential, the force constant matrix and vibrational modes of (10, 10) single-walled carbon nanotubes (SWCNTs) with monovacancy were calculated, based upon which their nonresonant Raman spectra were calculated by the empirical bond polarizability model. It was found that the monovacancy-induced Raman peaks lied out of the SWCNT' s G-band, which could be used to experimentally detect the monovacancy in SWCNT. In the calculations, it was found that the diameter of a SWCNT with monovacancy was almost the same as that of a perfect SWCNT. However, some new peaks in the R-band of the defective SWCNTs were found, which could be considered as a new kind of defective modes.