Thermomechanical properties of graphene: Valence force field model approach

摘要

Using the valence force field model of Perebeinos and Tersoff (2009 Phys. Rev. B 79 241409(R)), different energy modes of suspended graphene subjected to tensile or compressive strain are studied. By carrying out Monte Carlo simulations it is found that: (i)only for small strains (|ε|0.02) is the total energy symmetrical in the strain, while it behaves completely differently beyond this threshold; (ii)the important energy contributions in stretching experiments are stretching, angle bending, an out-of-plane term, and a term that provides repulsion against ππ misalignment; (iii)in compressing experiments the two latter terms increase rapidly, and beyond the buckling transition stretching and bending energies are found to be constant; (iv)from stretchingcompressing simulations we calculated the Youngs modulus at room temp.