Palaci I, Fedrigo S, Brune H, Klinke C, Chen M, Riedo E
School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, Georgia 30332, USA.
Phys Rev Lett. 2005 May 6;94(17):175502. doi: 10.1103/PhysRevLett.94.175502. Epub 2005 May 5.
We report an experimental and a theoretical study of the radial elasticity of multiwalled carbon nanotubes as a function of external radius. We use atomic force microscopy and apply small indentation amplitudes in order to stay in the linear elasticity regime. The number of layers for a given tube radius is inferred from transmission electron microscopy, revealing constant ratios of external to internal radii. This enables a comparison with molecular dynamics results, which also shed some light onto the applicability of Hertz theory in this context. Using this theory, we find a radial Young modulus strongly decreasing with increasing radius and reaching an asymptotic value of 30+/-10 GPa.
我们报告了一项关于多壁碳纳米管径向弹性随外半径变化的实验和理论研究。我们使用原子力显微镜并施加小的压痕幅度，以保持在线性弹性范围内。通过透射电子显微镜推断给定管半径的层数，揭示了外半径与内半径的恒定比率。这使得能够与分子动力学结果进行比较，分子动力学结果也为赫兹理论在此情况下的适用性提供了一些线索。使用该理论，我们发现径向杨氏模量随半径增加而强烈下降，并达到30±10 GPa的渐近值。
