Probing the Statistical Validity of the Ductile-to-Brittle Transition in Metallic Nanowires Using GPU Computing
| Autor: | Andrew P. Santos, Peter T. Cummings, Amulya K. Pervaje, William R. French, Christopher R. Iacovella |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Condensed Matter - Mesoscale and Nanoscale Physics Nanowire Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Computer Science Applications CUDA Molecular dynamics Brittleness Nano Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Statistical physics Physical and Theoretical Chemistry Graphics General-purpose computing on graphics processing units 0210 nano-technology Massively parallel |
| Popis: | We perform a large-scale statistical analysis (> 2000 independent simulations) of the elongation and rupture of gold nanowires, probing the validity and scope of the recently proposed ductile-to-brittle transition that occurs with increasing nanowire length [Wu et. al., Nano Lett., 12, 910-914 (2012)]. To facilitate a high-throughput simulation approach, we implement the second-moment approximation to the tight-binding (TB-SMA) potential within HOOMD-Blue, a molecular dynamics package which runs on massively parallel graphics processing units (GPUs). In a statistical sense, we find that the nanowires obey the ductile-to-brittle model quite well; however, we observe several unexpected features from the simulations that build on our understanding of the ductile-to-brittle transition. First, occasional failure behavior is observed that qualitatively differs from that predicted by the model prediction; this is attributed to stochastic thermal motion of the Au atoms and occurs at temperatures as low as 10 K. In addition, we also find that the ductile-to-brittle model, which was developed using classical dislocation theory, holds for nanowires as small as 3 nm in diameter. Finally, we demonstrate that the nanowire critical length is higher at 298 K relative to 10 K, a result that is not predicted by the ductile-to-brittle model. These results offer practical design strategies for adjusting nanowire failure and structure, and also demonstrate that GPU computing is an excellent tool for studies requiring a large number independent trajectories in order to fully characterize a system's behavior. To appear in Journal of Chemical Theory and Computation; 10 figures, 25 pages |
| Databáze: | OpenAIRE |
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