Molecular Dynamics Simulation of Mechanical Properties of Single-Crystal Bismuth Telluride Nanowire

Abstract

The mechanical properties of single-crystal bismuth telluride nanowires have been studied by molecular dynamics methods. The mechanical behavior of the Bi₂Te₃ nanowire for two principal axes was simulated under different strain rates at low temperature and the results compared with those of bulk Bi₂Te₃. The simulation results show that, due to its marked anisotropy, the nanowire shows quite different failure behaviors in the two directions, with the failure stress for the a-axis (4.7 GPa) being three times that for the c-axis (1.4 GPa). The stress–strain curve of the nanowire is different from that for Bi₂Te₃ bulk, as surface stress induced by atomic rearrangement significantly reduces the strength of the nanowire. The effect of strain rate on the mechanical properties of the nanowire has also been analyzed, showing that the failure stress and failure strain decrease with decreasing strain rate, a behavior not apparent in the bulk Bi₂Te₃ simulation.