Effect of Temperature on Elasticity of Silicon Nanowires

Abstract:

A semi-continuum approach is developed for mechanical analysis of a silicon nanowire, which captures the atomistic physics and retains the efficiency of continuum models. By using the Keating model, the strain energy of the nanowire required in the semi-continuum approach is obtained. Young’s modulus of the silicon (001) nanowire along [100] direction is obtained by the developed semi-continuum approach. Young’s modulus decreases dramatically as the size of a silicon nanowire width and thickness scaling down, especially at several nanometers, which is different from its bulk counterpart. The semi-continuum approach is extended to perform a mechanical analysis of the silicon nanowire at finite temperature. Taking into account the variations of the lattice parameter and the bond length with the temperature, the strain energy of the system is computed by using Keating anharmonic model. The dependence of young’s modulus of the nanowire on temperature is predicted, and it exhibits a negative temperature coefficient.

• Periodical: Key Engineering Materials (Volume 483)
• Pages: 526-531
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.483.526
• Online since: June 2011
• Authors: Jing Wang
• Keywords: Nanowire, Temperature, Young's Modulus

References

[1] X.X. Li, T. Ono, Y.L. Wang and M. Esashi: Appl. Phys. Lett. Vol. 83 (2003), p.3081.

[2] C.T. Sun, H. Zhang: J. Appl. Phys. Vol. 93 (2003), p.1212.

[3] P. N. Keating: Phys. Rev. Vol. 145 (1966), p.637.

[4] H. Rücker, M. Methfessel: Phys. Rev. B Vol. 52 (1995), p.11059.

[5] J.J. Wortman, R.A. Evans: J. Appl. Phys. Vol. 36 (1965), p.153.

[6] S.H. Park, J.S. Kim, J.H. Park, J.S. Lee, Y.K. Choi and O.M. Kwon: Thin Solid Films Vol. 492 (2005), p.285.

[7] Z. Tang, N.R. Aluru: Phys. Rev. B Vol. 74 (2006), p.235441.

[8] Z. Tang, H. Zhao, G. Li and N.R. Aluru: Phys. Rev. B Vol. 74 (2006), p.064110.