Molecular Dynamics Study of the Structural and Mechanical Properties of Skutterudite CoSb3: Surface Effect
Molecular dynamics simulations of the structural and mechanical properties of single-crystalline CoSb3 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 LAMMPS 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 single-crystalline CoSb3 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.