Overshooting phenomena of heat conduction in suspended graphene

Recent experiment and theoretical results show that thermal wave is more likely to occur in the low dimensional nonmetallic materials, such as graphene. In this article, based on the Guyer-Krumhansl model we derive the occurrence condition of the overshooting phenomenon in suspended graphene. This condition indicates that at the temperature 100 K if the size of suspended graphene is within the required range of about micro to millimeter, phonon transport is in the under-damped free oscillation regime and the overshooting can occur. Furthermore, we find that the overshooting phenomenon induced by the interference of thermal waves can cause the temperature in the heat conduction medium three times more than that of the temperature at the boundary, and the effective thermal conductivity of suspended graphene is more than six times of its bulk counterpart. Finally, an experimental plan to demonstrate the overshooting phenomenon (or second sound) in suspended graphene is proposed. (C) 2021 Elsevier B.V. All rights reserved.