Dresden 2006 – scientific programme
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O: Oberflächenphysik
O 4: Nanostructures I
O 4.3: Talk
Monday, March 27, 2006, 11:45–12:00, PHY C213
Atomic structure and electronic properties of self-assembled dysprosium-silicide nanowires on Si(001) — •Martina Wanke1, Christian Preinesberger1, Sylvia Hagedorn1, Gerd Pruskil1, Mario Dähne1, Denis Vyalikh2, Friedrich Schiller2, Sergeij Molodtsov2, and Clemens Laubschat2 — 1Institut für Festkörperphysik, Technische Universität Berlin, D-10623 Berlin — 2Institut für Festkörperphysik, Technische Universität Dresden, D-01219 Dresden
We report on high-resolution scanning tunneling microscopy of the self assembly of dysprosium-silicide nanowires on planar and vicinal Si(001) surfaces. These nanowires have widths of 15 to 100 Å and lengths exceeding several 1000 Å. They are found to grow in two domains with different nanowire directions on different substrate terraces, which is related to the geometry of the dangling bonds at the Si(001)2x1 surface. This two-domain growth can be suppressed when the nanowires are prepared on vicinal Si(001) substrates with an angle of 4∘ in [110] direction.
Two types of such nanowires are formed depending on the preparation conditions. Using high-resolution scanning tunneling microscopy, the atomic structure of both nanowire types is derived. It is shown that anisotropic strain in combination with the Si(001) surface anisotropy is the driving force for nanowire formation.
Angle-resolved photoelectron spectroscopy on vicinal substrates shows an anisotropic metallicity of the nanowires. Thus these nanowires are an interesting model system für one-dimensional metallicity. This project was supported by DFG, project number DA 408/11.