Thermal control of graphene morphology: a signature of its intrinsic surface tension

Abstract

The surface tension $σ$ of free-standing graphene is studied by path-integral simulations as a function of the temperature and the in-plane stress. Even if the applied stress vanishes, the membrane displays a finite surface tension $σ$ due to the coupling between the bending oscillations and the real area of the membrane. Zero-point effects for $σ$ are significant below 100 K. Thermal cooling drives the membrane from a planar to a wrinkled morphology. Upon heating the change is reversible and shows hysteresis, in agreement to recent experiments performed on supported graphene.

7 pages, 5 figures