Buckle or break

Researchers have performed large scale Monte Carlo simulations to determine the equilibrium structure of an infinite single graphene sheet over a range of temperatures. The graphene sheet forms ripples with a characteristic wavelength indicating that the ripples observed may not be original but an essential property. The environment of the carbon atoms in graphene must be considered to understand the origin of the ripples. The restoring forces perpendicular to the sheet are limited to the out-of-plane component of the forces between neighboring atoms due to the bending of the sheet. The strain energy limits the perpendicular displacements and keeps a finite membrane together. The membrane becomes stiffer due to the buckling, which increases the frequency of the perpendicular vibrational modes. The ripples may have an impact on the electronic properties of graphene. A buckling mechanism that originates from the flexibility of the carbon-carbon bonds can prove as a solution for graphene.