Temperature-dependent thermal expansion of graphene

In this paper the coefficient of thermal expansion of graphene is calculated by a new method based on the thermodynamics parameters. First, the graphene is investigated at zero temperature and then the changes made by temperature are studied. The Brenner many-body potential and harmonic oscillator model are employed to describe the interactions between carbon atoms in the graphene. The results show that the coefficient of thermal expansion of graphene is negative and tends toward zero by increasing the temperature which is in good agreement with reported experimental results. The approach presented in this paper can be used to predict theoretically the CTE of other structures of carbon such as nanotubes and composites.