Theoretical Analysis and Atomistic Modelling of Diffusion and Stability of Pure Element Hollow Nanospheres and Nanotubes
| Periodical | Defect and Diffusion Forum (Volume 277) |
|---|---|
| Main Theme | Diffusion and Diffusional Phase Transformations in Alloys |
| Edited by | D.Beke, A.Gusak, G.Murch, J.Philibert |
| Pages | 21-26 |
| DOI | 10.4028/www.scientific.net/DDF.277.21 |
| Citation | Alexander V. Evteev et al., 2008, Defect and Diffusion Forum, 277, 21 |
| Online since | April, 2008 |
| Authors | Alexander V. Evteev, Elena V. Levchenko, Irina V. Belova, Graeme E. Murch |
| Keywords | Atomistic Modeling, Defect, Diffusion, Embedded Atom Method (EAM), Hollow Nanospheres, Kinetic Monte Carlo, Molecular Dynamics (MD), Nanotube, Stability |
| Price | US$ 28,- |
A theoretical and atomistic study of diffusion and stability of a pure element hollow nanosphere and nanotube is performed. The shrinkage via the vacancy mechanism of these hollow nano-objects is described analytically. Using Gibbs-Thomson boundary conditions an exact solution of the kinetic equation in quasi steady-state at the linear approximation is obtained. The collapse time as a function of the geometrical sizes of the hollow nano-objects is determined. Kinetic Monte Carlo simulation of the shrinkage of these nano-objects is performed: it confirms the predictions of the analytical analysis. Next, molecular dynamics simulation in combination with the embedded atom method is used to investigate diffusion by the vacancy mechanism in a Pd hollow nanosphere and nanotube. It is found that the diffusion coefficient in a Pd hollow nanosphere and nanotube is larger near the inner and external surfaces compared with the middle part of a nanoshell. The molecular dynamics results provide quite a strong but indirect argument that a real pure element hollow nanosphere and nanotube may not shrink as readily via the vacancy mechanism as compared with the predictions of the analytical analysis and kinetic Monte Carlo simulations.
