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Rafat Mohammadi

Rafat Mohammadi

Academic rank: Associate Professor
ORCID: https://orcid.org/0000-0003-3675-4851
Education: PhD.
ScopusId: 6601987496
Faculty: Engineering
Address: Arak University
Phone:

Research

Title
A Molecular Dynamics Simulation Study of In- and Cross-Plane Thermal Conductivity of Bilayer Graphene
Type
JournalPaper
Keywords
bilayer graphene; in-plane thermal conductivity; cross-plane thermal conductivity non-equilibrium molecular dynamics; anisotropic thermal transport
Year
2023
Journal materials
DOI
Researchers Rafat Mohammadi ، Mohammadreza Ghaderi ، Ebrahim Hajian

Abstract

Efficient thermal management of modern electronics requires the use of thin films with highly an-isotropic thermal conductivity. Such films enable the effective dissipation of excess heat along one direction while simultaneously providing thermal insulation along the perpendicular direction. In this study, we investigate the thermal conductivity of bilayer graphene (BLG) sheets using non-equilibrium molecular dynamics, examining both in-plane and cross-plane thermal conduc-tivities. The in-plane thermal conductivity of 10 nm × 10 nm BLG with zigzag and armchair edges at room temperature is found to be around 204 W/m.K and 124 W/m.K, respectively. The in-plane thermal conductivity of BLG increases with sheet length. For all sizes, BLG with a zigzag edge ex-hibits higher thermal conductivity than that of the armchair edge, with this difference becoming more pronounced as the lengths of the sheets increase. In addition, increasing temperature from 300 K to 600 K decreases the in-plane thermal conductivity of a 10 nm× 10 nm zigzag BLG by about 34%. Similarly, the application of a 12.5% tensile strain induces a 51% reduction in its thermal conductivity compared to the strain-free values. Armchair configurations exhibit similar responses to variations in temperature and strain, but with less sensitivity. Furthermore, the cross-plane thermal conductivity of BLG at 300 K is estimated to be 0.05 W/m·K, significantly lower than the in-plane results by approximately four orders of magnitude. The cross-plane ther-mal conductance of BLG decreases with increasing temperatures, specifically, at 600 K, its value is almost 16% of that observed at 300 K.