Paper Title:
Vacancy Mediated Diffusion at Surface-Confined Atomic Intermixing
  Abstract

The present study deals with diffusion behavior of adsorbed atoms on stepped crystal surfaces. In volume-immiscible systems, two-dimensional (2D) atomic intermixing at epitaxial interface could be completely blocked on step-free surface domains. This is a result of high diffusion barrier for direct atomic exchange between adsorbed layer and substrate. In that case, diffusion takes place exclusively across the steps of atomic terraces. In such systems, dynamic competition between energy gain by mixing and substrate strain energy results in diffusion scenario where adsorbed atoms form alloyed stripes in the vicinity of terrace edges. At high temperatures, the stripe width increases and finally completely destroys the terraces. This process leads to formation of alloyed 2D atomic islands on top of pure substrate layer. The atomistic Monte Carlo simulations reveal vacancy-mediated mechanism of diffusion inside atomic terraces as a result of spontaneous generation of vacancies at high temperature. Being in agreement with recent experimental findings, the observed surface-confined alloying opens up a way various surface pattern to be configured at different atomic levels on the crystal surface.

  Info
Periodical
Solid State Phenomena (Volume 159)
Edited by
Lilyana Kolakieva and Roumen Kakanakov
Pages
121-124
DOI
10.4028/www.scientific.net/SSP.159.121
Citation
M. Michailov, "Vacancy Mediated Diffusion at Surface-Confined Atomic Intermixing", Solid State Phenomena, Vol. 159, pp. 121-124, 2010
Online since
January 2010
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Yan Mei Zhang, Xiao Hua Jie, Zhong Hou Li, Zhong Xu
1817