Dresden 2011 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 36: Poster Session II (Metals; Nanostructures at surfaces; Surface or interface magnetism; Spin-Orbit Interaction at Surfaces; Electron and spin dynamics; Surface dynamics; Methods; Theory and computation of electronic structure)

O 36.82: Poster

Dienstag, 15. März 2011, 18:30–22:00, P4

Growth mode and evolution of electronic properties for Bi_1−xSb_x alloys on W(110) — •Thomas Eelbo, Mike Gyamfi, Marta Waśniowska, and Roland Wiesendanger — Institute of Applied Physics, University of Hamburg, Jungiusstr. 11a, D-20355 Hamburg

Recent experiments show that the alloy of bismuth and antimony is a prominent example for topological insulators[1]. In order to systematically study the properties of Bi_1−xSb_x alloys on W(110), we firstly report on the early stage of Bi and Sb growth on W(110). The LEED and STM measurements reveal that Bi and Sb grow ordered in the pseudocubic (001) orientation. The growth mode was found to vary with thickness and temperature of the deposition for both films. For Bi thick films we observe prominent peaks in dI/dU spectra at -0.35 eV, +0.4 eV, +0.7 eV. However, for thick films of antimony a characteristic peak is observed at +0.6 eV. Furthermore we studied the growth mode and evolution of electronic properties of Bi_1−xSb_x alloys. The LEED images for different alloys exhibit hexagonal patterns, indicating (111) surfaces and STM topographies show a two-dimensional growth mode. STS measurements performed on the Bi_1−xSb_x alloy films on W(110) are consistent with the electronic structure obtained on the single crystal surface[1].

[1] P. Roushan et al., Nature 460, 1106 (2009)