Regensburg 2013 – scientific programme

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O: Fachverband Oberflächenphysik

O 22: Nanostructures at Surfaces II

O 22.10: Talk

Monday, March 11, 2013, 18:15–18:30, H45

Growth and properties of thin Bismuth films on vicinal Silicon substrates — •Christian Brand, Daniel Lükermann, Saddam Banyoudeh, Dennis Laube, Christoph Tegenkamp, and Herbert Pfnür — Institut für Festkörperphysik, Leibniz Universität Hannover, Germany

The semimetal Bismuth has recently come back into the focus of research due to its particular electronic properties. Low carrier concentrations in combination with small effective masses but high surface conductivity and a large Rashba splitting reveal thin Bismuth films as interesting object. Growth experiments of vicinal Bismuth films, which are expected to reveal topologically non-trivial edge states, were not performed so far. In the present work we studied the growth of ultra-thin Bismuth films on vicinal Si(557) substrates by means of SPA-LEED and STM/STS. (Sub-)Monolayer (ML) thin films as wetting-layer structures with (√3 × √3) reconstruction strongly influence the orientation and electronic properties of thicker Bismuth films (40 bilayers) grown on the substrate. Refacetting of the (557) surface occurs at low Bismuth coverages (and high temperatures) introducing (113) and (335) facets on the α-phase (1/3 ML), while (113) and (3 3 10) facets are formed on the so called γ-phase (2/3 ML). Only on the β-phase (1 ML) the initial step structure is preserved. In particular, stepped Bi(110) films with varying, but oriented rotational domains can be grown, while stepped and rotationally disordered Bi(111) films only grow on the α-phase. The steps have been characterized by first DC- and magneto-transport measurements.