Molecular Dynamics Simulation of Nanocluster Formation in a Supersonic Nano Nozzle Fabricated by Anodizing the Aluminum

Abstract:

A molecular dynamics method has been developed and applied for simulation of a supersonic Ne gas expansion through a convergingdiverging nozzle. Although the classical nucleation theory is able to explain some physics of the nucleation processes, however, due to the physical inaccuracy of the classical nucleation theory for small clusters, molecular dynamic method is more usable for studying gas flows having clusters. Pressure, flow velocity, temperature were parameters that extracted by MD method along the central x-axis. The nucleation and condensation of the clusters and their transient and equilibrium behavior are other parameters that are investigated in this simulation. The results show that although with suitable conditions the formation of clusters in a nanonozzle is possible, but the size of clusters is much smaller than its counterpart in macro scale and clusters with especial magic numbers are formed. The proposed novel method for fabrication this kind of nanonozzle is multi-step anodizing of the aluminum. This nanonozzle which can be fabricated experimentally can be used in Ionized Cluster Beam Deposition (ICBD) method.

• Periodical: Advanced Materials Research (Volume 829)
• Pages: 813-817
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.829.813
• Online since: November 2013
• Authors: Mohammad Hossein Tanhai, Shahyar Saramad*, Peyman Nayebi
• Keywords: Anodizing, Cluster, Molecular Dynamic (MD), Nanonozzle, Supersonic Expansion

References

[1] Z. Insepov, I. Yamada, Direct simulation Monte Carlo method for gas cluster ion beam technology, Nucl. Instr. and Meth. B 202 (2003) 283-288.

DOI: 10.1016/s0168-583x(02)01870-0

[2] James E.A. John. Gas dynamics, 2nd Ed., Prentice-Hall, New Jersey, (1969).

[3] S.H. Bauer, D. Frurip, A self-consistent kinetic model, J. Phys. Chem. 81 (1977) 1015-1024.

[4] A. Eftekhari, Nano structured materials in electrochemistry, Wiley- VCH, Weinheim, (2008).

[5] T. Nagaura, F. Takeuchi, S. Inoue, "fabrication and structural control of anodic alumina films with inverted cone porous structure using multi-step anodizing, Electrochimia Acta. 53 (2008) 2109-2114.

DOI: 10.1016/j.electacta.2007.09.016

[6] P.A. Skovorodko, Proceedings of the 13th International Conference on Rarefied Gas Dynamics, Novosibirsk, (1982)10-53.

[7] B.M. Smirnov, Surface melting of clusters, Phys. Scr. 50 (1994) 31-64.