Regensburg 2019 – wissenschaftliches Programm
O 95.9: Vortrag
Freitag, 5. April 2019, 12:30–12:45, H14
Tb induced surface structures on Si(110) — •Stephan Appelfeller and Mario Dähne — Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
Metallic rare earth silicide nanostructures are known to form by deposition of rare earth elements on clean Si substrates and annealing. The growth of nanowires is observed on Si(001) substrates due to anisotropic strain and on Si(hhk) substrates due to steps disrupting the two-dimensional film growth found on Si(111) substrates. Such rare earth silicide nanowires are not only interesting for studying the unique one-dimensional physics, but are also promising for future applications since they consist of the metallic bulk silicides, possibly allowing their passivation by capping without strong changes of their properties.
Here, the growth of Tb induced surface structures on the Si(110) surface is studied. Using scanning tunneling microscopy, single domain growth of Tb silicide structures with very high aspect ratios, i.e. of Tb silicide nanowires, is observed even on planar substrates due to its structural anisotropy. Furthermore, scanning tunneling spectroscopy clearly shows that these nanowires have a finite density of states at the Fermi level. In contrast, the wetting layer, which accompanies the nanowires formation, is characterized by a small band gap. This wetting layer is also studied using low energy electron diffraction revealing the formation of two domains.
This work was supported by the DFG, FOR 1700, project E2.