Inhalt des Dokuments
Silicide nanowires
After our discovery of the self-organized formation of rare earth silicide nanowires on the Si(001) surface [1], we studied a variety of such nanowire systems in detail. Tuning the rare earth coverage and the thermal treatment, two different (quasi) one-dimensional structures can be prepared, a wire-like wetting layer showing a 2x7 reconstruction as well as free-standing nanowires that often form bunches [2-5]. The nanowire formation is presumably induced by an anisotropic strain in the silicide. On vicinal Si(001) surfaces, a unidirectional nanowire growth is obtained [2-5]. From ARPES data we found that the nanowires are metallic with a one-dimensional electron energy dispersion [2-4].
On Si(557), which is a vicinal surface of Si(111), also nanowires were observed due to the stepped structure of the Si(557) surface [4,6]. These DySi2 nanowires are characterized by a two-dimensional metallicity, similar to DySi2 thin films on Si(111).
This work is currently supported by FOR1700 project E2 of the Deutsche Forschungsgemeinschaft.
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[2] Structure and electronic properties of dysprosium silicide nanowires on vicinal Si(001), C. Preinesberger, G. Pruskil, S.K. Becker, M. Dähne, D.V. Vyalikh, S.L. Molodtsov, C. Laubschat, and F. Schiller, Appl. Phys. Lett. 87, 083107 (2005).
[3] Electronic properties of self-assembled rare-earth silicide nanowires on Si(001), M. Wanke, K. Löser, G. Pruskil, D. Vyalikh, S.L. Molodtsov, S. Danzenbächer, C. Laubschat, and M. Dähne, Phys. Rev. B 83, 205417 (2011).
[4] Metallic rare-earth silicide nanowires on silicon surfaces, M. Dähne and M. Wanke, J. Phys.: Condens. Matter 25, 014012 (2013).
[5] Tb silicide nanowire growth on planar and vicinal Si(001) surfaces, S. Appelfeller, S. Kuls, and M. Dähne, Surf. Sci. 641, 180 (2015).
[6] Electronic properties of dysprosium silicide nanowires on Si(557), M. Wanke, M. Franz, M. Vetterlein, G. Pruskil, C. Prohl, B. Höpfner, P. Stojanov, E. Huwald, J. Riley, and M. Dähne, J. Appl. Phys. 108, 064304 (2010).