Research Progress on Thermal Conductivity of Two-dimensional IV A Materials Based on Molecular Dynamics Simulation

This paper introduces the research process of using molecular dynamics theory to simulate the thermal conductivity of two-dimensional IV A materials represented by graphene. The major works include using Materials Studio to construct the material model, importing the model into Lammps for simulation calculation, and using non-equilibrium molecular dynamics (NEMD) to calculate the thermal conductivity. The relationship between thermal conductivity and model size of several two-dimensional IV A materials is summarized. With the increase of size, the thermal conductivity increases. Moreover, the thermal conductivity increases approximately linearly with the increase of length and nonlinear with the increase of width, which shows that the first derivative of the function of thermal conductivity and width decreases gradually with the increase of width, but it is always positive. The relationship between thermal conductivity and temperature is summarized as well. The thermal conductivity increases with the increase of temperature, and the thermal conductivity has the maximum value with respect to the first derivative of the initial temperature around 330K, but some literatures have given the opposite experimental results: the thermal conductivity decreases with the increase of temperature. The molecular dynamics simulation process and influencing factors of thermal conductivity of two-dimensional IV A materials that are studied in this paper play a certain role in the field of low-dimensional thermal properties.