Ba-Filling Effect on the Uniaxial Tensile and Compressive Mechanical Behavior of Crystalline CoSb₃: A Molecular Dynamics Study

Filled skutterudites, which possess application potential, are believed to be a class of novel thermoelectric materials. The contribution of atomic filling to the significant decrease of phonon conductivity is investigated extensively in the literature. However, the filling effect on the fundamental mechanical behavior is not so far very clear. In the present study, molecular dynamics simulations have been performed to investigate the effect of Ba-filling on the uniaxial tensile and compressive mechanical properties of crystalline CoSb₃ with a multibody interatomic potential. First, we constructed the fully Ba-filled CoSb₃ model according to the ideal lattice structure. For comparison, pure binary CoSb₃ was also modeled. Then, the simulation models were relaxed to reach more favorable configurations. Thereafter, the uniaxial tension and compression were carried out by strain-controlling until failure at room temperature. Stress–strain curves were obtained during the whole deformation process. The atomic rearrangements and failure patterns were also examined. The comparison of these mechanical responses between the filled and unfilled CoSb₃ was made and analyzed. The results are expected to be helpful for the application of high-performance skutterudites.