Atomistic modeling of thermo‐mechanical properties of cubic SiC

Abstract

SiC is an important multifunctional material with application in electronics and as a structural material. Many investigations of SiC have been done using both classical molecular dynamics and first principles methods. However, they are of limited scope and, in particular, SiC properties at finite temperatures have not been adequately evaluated. The good mechanical, thermal, and chemical properties of SiC such as high stiffness, high hardness, high mechanical strength at high temperature, and high thermal conductivity, make SiC a candidate for various applications in nuclear industries. In this work, we evaluated thermomechanical properties at finite temperatures obtained by LAMMPS code with traditionally used Tersoff potential (TR89 with PRB 41 correction), and the newer GW 2002 (GW02) potential. We compared them with the calculations made using MEAM 1995 (MEAM 95) and with our first principles DFT predictions. It is demonstrated that the thermal expansion and mechanical properties calculated as a function of temperature for classical potentials TR89 and GW02 do not agree well with first principles calculations while better agreement is found for the MEAM95 potential. Classical molecular dynamics calculations made with the use of two earlier potentials under‐predict thermal conductivity by one order of magnitude for the TR89 potential and by more than 30% for the GW02.

Effect of Nanoscale in Situ Interface Welding on the Macroscale Thermal Conductivity of Insulating Epoxy Composites: A Multiscale Simulation Investigation

“…and Szpunar et al . are in good agreement, , which are the basis for the following Monte Carlo simulation of the interfacial heat transfer of the CVI-SiC-welded BN–BN interfaces.…”

“…All first-principles calculations were performed in the QUANTUM ESPRESSO software based on an h-BN supercell ( a = b = 2.478 Å, c = 6.425 Å 2 , 5 × 5 × 2) and a β -SiC ( i . e ., CVI-SiC) supercell ( a = b = c = 4.357 Å, 3 × 3 × 3), whose k -point samplings were set to the gamma-centered mesh of 2 × 2 × 1 and 1 × 1 × 1, respectively. The harmonic interatomic force constants (IFCs) and phonon properties were obtained using the phonopy package through the density functional perturbation theory (DFPT) method .…”

“…72 At room temperature, the bulk h-BN monocrystal possesses high inplane TC (447 W/(m•K)) and low through-plane TC (27 W/ (m•K)), while the TC of isotropic β-SiC reaches 442 W/(m• K). The calculated TC values and the reported results of Jiang et al and Szpunar et al are in good agreement, 72,74 which are the basis for the following Monte Carlo simulation of the interfacial heat transfer of the CVI-SiC-welded BN−BN interfaces.…”

Comparison and Assessment of Different Interatomic Potentials for Simulation of Silicon Carbide

“…Moreover, Vashishta potential shows agreement with experimental results, except for C 44 for 3C-SiC [ 27 ]. In the field of thermal properties, most studies have focused on the thermal conductivity of 3C-SiC [ 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ] and 4H-SiC [ 35 ]. The research revealed that compared with T89 potential, the thermal conductivity predictions by GW potential closely match the experimental results [ 32 ].…”

Interfacial thermal resonance in an SiC–SiC nanogap with various atomic surface terminations

“…Silicon carbide (SiC) has shown great potential in high-power devices because of its outstanding properties, such as high thermal conductivity, wide band gap, and high electric breakdown field. [1][2][3][4][5] The polytypes of SiC that are most widely employed in micro-and nanoelectronics include 3C-SiC, 4H-SiC, and 6H-SiC, of which the cubic crystallization of SiC is unique to 3C-SiC. 6 With the increasing miniaturization and integration of electronic devices, heat dissipation is now an essential issue restricting their development.…”