Abstract
Molecular dynamics has been used to simulate the uniaxial compression of single crystal silicon nanospheres using the Tersoff potential. The resulting yield behavior is shown to vary with changes in temperature, sphere size, and crystallographic orientation with respect to the loading direction. Only compression along the [1 0 0] crystallographic direction resulted in the formation of the β-Sn phase. A temperature dependent hardening response is observed in all orientations independent of the β-Sn phase transformation. Dislocation activity is detected at elevated temperatures in the largest sphere indicating a critical temperature and size for nucleation. Consequences of these dislocations to simulating strength properties at the nanoscale are discussed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1651-1660 |
| Number of pages | 10 |
| Journal | Computational Materials Science |
| Volume | 50 |
| Issue number | 5 |
| DOIs | |
| State | Published - Mar 2011 |
Bibliographical note
Funding Information:This work was partially supported in part (RB and LMH) by the National Science Foundation Grant NSF_CMMI 0800896. One of us (WWG) would like to acknowledge additional support of the Air Force through an AOARD-08-4131 program dedicated to understanding plasticity and fracture in hard materials and the Abu Dhabi-Minnesota Institute for Research Excellence (ADMIRE); a partnership between the Petroleum Institute (PI) of Abu Dhabi and the Department of Chemical Engineering and Materials Science of the University of Minnesota. Additionally, four of us (LMH, XZ, JAZ, and NMR) were supported by Sandia, Livermore. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DEAC04-94AL85000.
Keywords
- Dislocations
- Molecular dynamics
- Nanostructure
- Phase transformations
- Silicon