First principles study of the Young's modulus of Si <001> nanowires
We report the results of first-principles calculations of the Young's modulus and other mechanical properties of hydrogen-passivated Si <001> nanowires. The nanowires are taken to have predominantly {l_brace}100{r_brace} surfaces, with small {l_brace}110{r_brace} facets according to the Wulff shape. The Young's modulus, the equilibrium length and the constrained residual stress of a series of prismatic beams of differing sizes is found to have a size dependence that scales like the surface area to volume ratio for all but the smallest beam. The results are compared with two different models (and the results of classical atomistic calculations based on an empirical potential). We discuss the physics of the hydrogen interactions on the surface and the charge density variations within the beam that may account for the discrepancies of the models and the first principles results.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 900085
- Report Number(s):
- UCRL-JRNL-222598; TRN: US200709%%376
- Journal Information:
- Physical Review B, vol. 75, N/A, January 16, 2007, pp. 041305(R), Journal Name: Physical Review B, vol. 75, N/A, January 16, 2007, pp. 041305(R)
- Country of Publication:
- United States
- Language:
- English
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