Nano Express

Nanoscale Research Letters

, Volume 4, Issue 12, pp 1447-1451

Open Access This content is freely available online to anyone, anywhere at any time.

The Influence of an Adsorbate Layer on Adatom Diffusion and Island Nucleation: Fe on \(\hbox{Si(111)-}\sqrt{3} \times \sqrt{3} \hbox{-Au}\)

  • K. ParedisAffiliated withInstituut voor Kern- en Stralingsfysica and INPAC Email author 
  • , D. SmeetsAffiliated withInstituut voor Kern- en Stralingsfysica and INPAC
  • , A. VantommeAffiliated withInstituut voor Kern- en Stralingsfysica and INPAC


Using scanning tunneling microscopy, the influence of a thin Au layer on the diffusion of Fe adatoms and the subsequent island nucleation on a Si(111) surface is investigated. The adsorbate induces the \(\hbox{Si(111)-}\sqrt{3}\times \sqrt{3} \hbox{-Au} \) structure that increases the surface mobility of subsequently deposited Fe atoms, resulting in the formation well-defined nanoclusters. Surprisingly, the domain walls—inherent to the \(\sqrt{3} \times \sqrt{3} \hbox{-Au} \) reconstruction—do not influence the surface diffusion, which demonstrates that the passivation is of much more importance for the self-assembly than the surface corrugation. Using the decoupling of the diffusion and nucleation on the surface and the reaction with the surface and conventional nucleation theory, the activation energy for surface diffusion E d = 0.61 eV and the critical cluster size i = 3 are determined, which reveal the microscopic details of the diffusion and nucleation processes.


Self-assembly Surface reconstruction Diffusion Passivation STM Nanostructures Iron silicide