Atomic diffusion on vicinal surfaces: step roughening impact on step permeability

18th International School on Condensed Matter Physics: "Challenges of Nanoscale Science: Theory, Materials, Applications"

Ranguelov, B.^1 ; Michailov, M.^1

Institute of Physical Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Sofia

1113, Bulgaria^1

关键词: Atomic diffusions;    Computational model;    Diffusion control;    Epitaxial interfaces;    Nanoscale patterning;    Physical phenomena;    Simultaneous effects;    Step permeability;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/558/1/012004/pdf
DOI  :  10.1088/1742-6596/558/1/012004

来源: IOP

【 摘 要 】

The problem of mass transport in material science for systems with reduced dimensionality holds special academic and technological attention since the fine diffusion control of adatoms could initiate exotic nanoscale patterning at epitaxial interfaces. The present study brings out important details of the atomic diffusion mechanisms on vicinal surfaces, accounting for the subtle competition between an external field imposed on the migrating adatoms and the roughening of the steps bordering the atomic terraces. The computational model reveals a temperature gap for breakdown of step permeability in the vicinity of the step roughening transition and sheds light on recently observed experimental results for atomic step dynamics on Si surfaces. The present study also demonstrates the extended capability of atomistic models in computer simulations to unravel simultaneous effects, to distinguish between them, and finally to assess their specific contribution to experimentally observed complex physical phenomena.