The temperature dependence of the thermo-mechanical behavior of materials is of great importance in many engineering applications where the precise properties of materials over an extended temperature range are needed. The objective of this work is to present a density functional study to predict the temperature variation of Young’s modulus of graphene. To this end, the energies of phonons as well as thermodynamic functions are calculated from phonon calculations via the quasi-harmonic approximation. It is observed that with the increase of strain the phonon energy decreases. Also, by increasing temperature up to a special value which is around 400 K, Young’s modulus decreases appreciably. For the temperatures higher than 400 K, Young’s modulus decreases with a lower rate and tends to be constant at high temperatures. The results obtained are in a good agreement with the experimental data previously reported in the literature.

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