Exploring the thermal conductivity and mechanical properties of BN-doped graphyne.

Abstract

The present study focuses on the thermo-mechanical modelling of pristine graphyne, BN-substituted graphyne, and graphyne-like BN utilizing molecular dynamics (MD) simulation. Considering the results of uniaxial tensile MD simulations, respective structures indicate outstanding mechanical properties. In particular, the pristine graphyne (note that it only consists of C-C atomic bond type) has superior mechanical properties compared to others. Besides, graphyne-like BN demonstrates the lowest mechanical properties due to consisting of only B-N bonds. MD simulations are conducted for different temperatures and strain rates varying between 1K-1200K and 107s-1-109s-1, respectively. With increasing temperature, a gradual decrease in mechanical properties is observed due to the high temperature's weakening effect. Mechanical properties of graphyne-like BN are affected by the change in temperature more than other structures. Furthermore, findings of MD simulation show that the mechanical properties of aforementioned structures have an increasing trend with increasing strain rates. Similar to mechanical properties, pristine graphyne, BN-substituted graphyne, and graphyne-like BN have superior thermal conductivity (TC) properties. Non-equilibrium MD simulation results illustrate that the pristine graphyne containing C-C bonds exhibits the largest TC value. In contrary, the graphyne-like BN comes up with a low TC value. Temperature increase (from 200 to 900K) affects TC values negatively owing to increase in phonon-phonon scattering. Finally, the results of this study make aforementioned structures a splendid competitor for thermo-mechanical practice of 2D-based structures.