Novel Defects and Anisotropic Vacancy Diffusion on Reconstructed Surfaces

1999 ◽  
Vol 585 ◽  
Author(s):  
O. Rodríguez De La Fuente ◽  
M. A. González ◽  
J. M. Rojo
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Anisotropic Diffusion ◽  
Previous Investigation ◽  
Diffusion Mechanism ◽  
Vacancy Diffusion ◽  
Reconstructed Surfaces ◽  
Intermediate States ◽  
Topmost Layer ◽  
Dynamics Simulations

AbstractSTM and molecular dynamics simulations are used to study Au(001) 5×25 reconstructed surfaces after Ar+ bombardment at 600 eV and ion doses from 0.05 to 1 ML+. Surface 2D dislocation dipoles, identified as such in a previous investigation, are shown to have dislocation properties and to be formed by anisotropic diffusion of surface vacancies along the ridges of the reconstructed topmost layer. A new vacancy diffusion mechanism involving intermediate states with de-localized vacancies is identified. Increasing ion fluences is shown to lead to the formation of vacancy islands that are nucleated at the dislocation dipoles.

Size-Dependent Elasticity of Silicon Nanowires

2009 ◽  
Vol 60-61 ◽  
pp. 315-319 ◽  
Author(s):  
W.W. Zhang ◽  
Qing An Huang ◽  
H. Yu ◽  
L.B. Lu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Silicon Nanowires ◽  
First Principles ◽  
Si Nanowires ◽  
Size Dependent ◽  
Reconstructed Surfaces ◽  
Strain Relationship ◽  
Dynamics Simulations ◽  
Good Agreement

Molecular dynamics simulations are carried out to characterize the mechanical properties of [001] and [110] oriented silicon nanowires, with the thickness ranging from 1.05nm to 3.24 nm. The nanowires are taken to have ideal surfaces and (2×1) reconstructed surfaces, respectively. A series of simulations for square cross-section Si nanowires have been performed and Young’s modulus is calculated from energy–strain relationship. The results show that the elasticity of Si nanowires is strongly depended on size and surface reconstruction. Furthermore, the physical origin of above results is analyzed, consistent with the bond loss and saturation concept. The results obtained from the molecular dynamics simulations are in good agreement with the values of first-principles. The molecular dynamics simulations combine the accuracy and efficiency.

The Diffusion Isotope Effect and Diffusion Mechanism in Liquid Cu-Ag and Cu-Ni Alloys

2021 ◽  
Vol 413 ◽  
pp. 136-145
Author(s):  
Ujjal Sarder ◽  
Tumpa R. Paul ◽  
Irina V. Belova ◽  
Graeme E. Murch
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Isotope Effect ◽  
Composition Dependence ◽  
Diffusion Mechanism ◽  
Liquid Alloys ◽  
Ni Alloys ◽  
Effect Parameter ◽  
Dynamics Simulations ◽  
And Diffusion

In this paper, the diffusion isotope effect and diffusion mechanism are investigated by means of molecular dynamics simulations in two liquid alloys, Ni-Ag and Ni-Cu. The values for the diffusion isotope effect parameter allow for the estimate of the number of atoms which are moving cooperatively in a basic diffusion event as experienced by a given atomic species. It is shown that the composition dependence of ND is typically very small. However, the temperature dependence of this parameter is much more pronounced. In addition, it is shown that, on average, in these alloys and temperatures considered, ND is limited to the range: 5<ND<17. This is consistent with results of molecular dynamics simulations on the average coordination number calculations. This would suggest that, together with a given atom, depending on temperature, the neighbouring atoms are all involved in the basic diffusion event.

Molecular dynamics simulations of oxygen vacancy diffusion in SrTiO3

2012 ◽  
Vol 24 (48) ◽  
pp. 485002 ◽  
Author(s):  
Marcel Schie ◽  
Astrid Marchewka ◽  
Thomas Müller ◽  
Roger A De Souza ◽  
Rainer Waser
Keyword(s):  
Molecular Dynamics ◽  
Oxygen Vacancy ◽  
Molecular Dynamics Simulations ◽  
Vacancy Diffusion ◽  
Dynamics Simulations ◽  
Oxygen Vacancy Diffusion
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