Dubay O, Kresse G, Kuzmany H
Institut für Materialphysik, Universität Wien and Center for Computational Material Science, Sensengasse 8, A-1090 Wien, Austria.
Phys Rev Lett. 2002 Jun 10;88(23):235506. doi: 10.1103/PhysRevLett.88.235506. Epub 2002 May 28.
The radial dependency of the vibrational frequencies of single-wall carbon nanotubes in the G band (1500-1600 cm(-1)) is studied by density functional theory. In metallic nanotubes, a mode with A1 symmetry is found to be significantly softer than the corresponding mode in insulating tubes or graphite. The mechanism that leads to the mode softening is explored. It is reminiscent of the driving force inducing Peierls distortions. At ambient temperature, the energy gained by opening the gap is, however, not sufficient for a static lattice distortion. Instead the corresponding vibrational frequency is lowered.
通过密度泛函理论研究了单壁碳纳米管在G带（1500 - 1600 cm⁻¹）中振动频率的径向依赖性。在金属纳米管中，发现具有A1对称性的模式比绝缘管或石墨中的相应模式明显更软。探讨了导致模式软化的机制。这让人联想到诱导佩尔斯畸变的驱动力。然而，在室温下，打开能隙所获得的能量不足以产生静态晶格畸变。相反，相应的振动频率会降低。
