| Author | P. Keblinski & P.K. Schelling |
|---|---|
| Title | Comment on "Thermal Contraction of Carbon Fullerenes and Nanotubes" |
| Year | 2005 |
| Journal | Physical Review Letters |
| Volume | 94 |
| Pages | 701 |
| Editor | The American Physical Society |
| Abstract | Using a tight-binding based energy functional parametrized to ab initio density-functional calculations [1], Kwon et al. performed classical molecular-dynamics simulations of the thermal expansion of C60 molecules and (10; 10) single-walled carbon nanotubes. The key result reported in a recent Letter [2] is that both C60 and nanotubes exhibit zero thermal expansion coefficient, , at T = 0, that, with increasing temperature, first becomes negative and then turns positive at higher temperatures. They noted that this temperature dependence was in agreement with the experimentally observed in-plane thermal expansion of graphite. Most of the simulation of Kwon et al. is for temperatures well below Debye temperatures of C60 and nanotubes, where the majority of the vibration modes (phonons) are quantum mechanically frozen [3,4]. This freezing is, however, not captured by classical simulations; thus the agreement of the simulation results with experimental data is accidental. |
| PDF File |  Download |