Effect of Uniaxial Strain on Heat Capacity and Thermal Conductivity of Graphene Nanoribbons Passivated by Hydrogen

Abstract

First-principle calculation is used to study the influence of uniaxial strain on the heat capacity and thermal conductivity of hydrogen passivated graphene nanoribbons. It is found that, the frequency of lattice vibration modes shifts down with increasing strain, and the thermodynamic properties change correspondingly, which is also temperature dependent. At the temperature lower than 200 K, the influence of strain is negligible, while at the temperature higher than 200 K, more phonon modes will be activated at a larger strain. The heat capacity is increased to some degree, however, the thermal conductivity increases firstly and then decreases with the strain. This can be ascribe to the enhanced Umklapp scattering among phonons and is consistent with the result of vibration entropy.