The thermal expansion coefficient (TEC) of single-layer graphene is estimated with temperature-dependent Raman spectroscopy in the temperature range between 200 and 400 K. It is found to be strongly dependent on temperature but remains negative in the whole temperature range, with a room temperature value of -8.0x10^{-6} K^{-1}. The strain caused by the TEC mismatch between graphene and the substrate plays a crucial role in determining the physical properties of graphene, and hence its effect must be accounted for in the interpretation of experimental data taken at cryogenic or elevated temperatures.
@article{arxiv.1107.2469,
title = {Negative Thermal Expansion Coefficient of Graphene Measured by Raman Spectroscopy},
author = {Duhee Yoon and Young-Woo Son and Heonsik Cheong},
journal= {arXiv preprint arXiv:1107.2469},
year = {2011}
}
Comments
17 pagese, 3 figures, and supporting information (4 pages, 3 figures); Nano Letters, 2011