Young's modulus of Graphene: a molecular dynamics study

TL;DR

This study uses molecular dynamics to investigate how graphene's Young's modulus varies with size, temperature, and isotopic disorder, providing insights consistent with experimental data.

Contribution

It introduces a molecular dynamics method to analyze the size, temperature, and disorder dependence of graphene's Young's modulus, aligning well with experimental results.

Findings

Young's modulus increases with size and saturates.

Young's modulus rises from 0.95 TPa to 1.1 TPa with temperature.

Young's modulus is insensitive to low-level isotopic disorder.

Abstract

The Young's modulus of graphene is investigated through the intrinsic thermal vibration in graphene which is `observed' by molecular dynamics, and the results agree quite well with the recent experiment [Science \textbf{321}, 385 (2008)]. This method is further applied to show that the Young's modulus of graphene: 1. increases with increasing size and saturation is reached after a threshold value of the size; 2. increases from 0.95 TPa to 1.1 TPa as temperature increases in the region [100, 500]K; 3. is insensitive to the isotopic disorder in the low disorder region ($< 5%$), and decreases gradually after further increasing the disorder percentage.