tailieunhanh - Báo cáo hóa học: " The Influence of an Adsorbate Layer pffiffiffi Adatom Diffusion on pffiffiffi and Island Nucleation: Fe on Si(111)- 3 Â 3-Au"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: The Influence of an Adsorbate Layer pffiffiffi Adatom Diffusion on pffiffiffi and Island Nucleation: Fe on Si(111)- 3 Â 3-Au | Nanoscale Res Lett 2009 4 1447-1451 DOI s11671-009-9418-3 NANO EXPRESS The Influence of an Adsorbate Layer on Adatom Diffusion and Island Nucleation Fe on Si 111 - 3 X ự3-Au K. Paredis D. Smeets A. Vantomme Received 5 June 2009 Accepted 12 August 2009 Published online 26 August 2009 to the authors 2009 Abstract 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 Si 111 -v3x 3-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 t 3 X ựĩ-Au reconstruction do not influence the surface diffusion which demonstrates that the passivation is of much more importance for the selfassembly 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 Ed eV and the critical cluster size i 3 are determined which reveal the microscopic details of the diffusion and nucleation processes. Keywords Self-assembly Surface reconstruction Diffusion Passivation STM Nanostructures Iron silicide Introduction In order to assure the continuing downscaling of electronic components new growth methods need to be explored as currently used top-down techniques are approaching their physical limits. An emerging alternative for the growth of nanoscale systems is self-assembly by exploiting the K. Paredis El D. Smeets A. Vantomme Instituut voor Kern- en Stralingsfysica and INPAC K. U. Leuven Celestijnenlaan 200D 3001 Leuven Belgium e-mail striving toward the minimal energy it enables the formation of nanostructures even down to the atomic level. However its future implementation requires extensive fundamental research to unravel the .