Molecular Dynamics Simulation on Mechanics of Skutterudite CoSb3 Nanowire

For the binary thermoelectric material CoSb3 with a complex crystal structure, the Morse potential functional form is employed to describe its three-dimensional atomic interactions. The mechanical responses and deformation behavior of a rectangular cross-section CoSb3 nanowire subjected to uniaxial tensile strain are simulated at constant temperature by the molecular dynamics method. The deformation is strain controlled with constant strain rate. When the strain increases, necking gradually becomes distinct near the middle of the model, and complete damage occurs at around 60% strain. The single-crystal CoSb3 nanowire exhibits properties distinct from those of single-crystal CoSb3 bulk previously studied. Comparison of the stress–strain curves and configuration evolutions of the CoSb3 nanowire and bulk during tensile loading indicate that an interesting brittle–ductile transition phenomenon occurs when the single-crystal CoSb3 varies from bulk to nanowire. Future efforts should be devoted to seeking the critical dimension at which this transition happens and the mechanism behind it.