Molecular Dynamics Study of the Structural and Mechanical Properties of Skutterudite CoSb3: Surface Effect

Abstract

Molecular dynamics simulations of the structural and mechanical properties of single-crystalline CoSb 3 have been carried out at room temperature. Special emphasis was given to the surface effect. Four different boundary conditions were applied to represent a wide range of surface-atom fractions. The LAM-MPS program in conjunction with a multibody potential was employed. First, free relaxation was performed to obtain the corresponding stable configurations. The atomic rearrangements and energy distributions were observed. Then, uniaxial tensile deformation was simulated at a constant strain rate. The stress-strain responses and structural evolutions were examined during the process. Comparison of simulation results between different boundary conditions was carefully made. It was found that, when the scale of the singlecrystalline CoSb 3 model becomes nanometric and the fraction of the surface atoms increases, the mechanical performance becomes substantially worse. Nonetheless, the deformation mechanism and intrinsic mechanical nature are very similar.

Thermal transport across the CoSb3–graphene interface

“…19 The Morse and Cosine-square potentials 20,21 were used to describe the interactions of Co–Sb within CoSb 3 , which have been used to investigate the thermal transport properties and mechanical properties accurately. 22–26 A weak van der Waals force between CoSb 3 and graphene was described using the Lennard-Jones (LJ) potentialwhere r ij is the distance between two atoms and ε ij and σ ij are the energy and distance constants, respectively. The LJ potential parameters used in this simulation, shown in Table 1, are calculated using a universal force field (UFF) model.…”