Use of Molecular Dynamics Simulations to Study the Effects of Nanopores and Vacancies on the Mechanical Properties of Bi2Te3
Y Li and KY Cai and B Huang and GD Li and LS Liu and PC Zhai, JOURNAL OF ELECTRONIC MATERIALS, 43, 1824-1828 (2014).
The effects of nanopores and vacancies on the mechanical properties of Bi2Te3 have been studied. Cuboid single-crystal bulk Bi2Te3 with atoms removed was chosen for molecular dynamics simulations. The mechanisms of action of the two defects can be distinguished by their specific effects on the crystal structure of the bulk Bi2Te3. The mechanical properties of the nanoporous Bi2Te3 are affected by porosity (I center dot), surface-to-volume ratio (rho), and minimum cross-section length (L (min)). The elastic modulus remains unchanged at 52.86 GPa for constant porosity of 0.7% whereas the ultimate stress and fracture strain gradually decrease with growing rho or decreasing L (min). The lattice stability of Bi2Te3 gradually weakens as the proportion of vacancies increases; this leads to increasing potential energy and poorer mechanical properties of Bi2Te3. When the proportion of Bi vacancies is increased from 0% to 8%, the elastic modulus decreases from 57.17 GPa to 36.32 GPa, a reduction of 36.47%, the ultimate stress decreases from 6.40 GPa to 3.61 GPa, a reduction of 43.59%, and the fracture strain decreases from 22.4% to 13.8%, a reduction of 38.39%.
Return to Publications page