Regensburg 2016 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 18: Metallic Nanowires on Semiconductor Surfaces
O 18.9: Poster
Montag, 7. März 2016, 17:00–19:30, Poster A
Raman spectroscopy of quasi-1D nanowires on the Si(553)-Au surface — •Julian Plaickner1, Sandhya Chandola1, Eugen Speiser1, Norbert Esser1, Benedikt Halbig2, Jean Guerts2, Julian Aulbach3, Jörg Schäfer3, Sergej Neufeld4, and Simone Sanna4 — 1Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Berlin — 2Universität Würzburg, Experimentelle Physik III, Würzburg — 3Universität Würzburg, Experimentelle Physik IV, Würzburg — 4Fakultät für Naturwissenschaften, Department Physik, Universität Paderborn
Vicinal Si(111) substrates offer an additional control parameter (terrace width) for growth of atomic gold chains on Si(111) terraces. Moreover, a new one-dimensional so-called Si honeycomb-like structure is generated, the latter exhibiting spin polarization effects at low temperature, according to calculations [1], accompanied by small structural changes at the step edges. Optical methods such as Reflectance Anisotropy Spectroscopy (RAS) and Raman spectroscopy have been shown to be sensitive tools to verify surface structure of such nanostructures. Here we concentrate on a study of the surface phonon modes of the Si(553)-Au-(5x2) surface by Surface Raman Spectroscopy.
Raman spectra Si(553)-Au-(5x2) surface show clear signatures of Au- and Si related surface vibrations, while RAS shows signatures of electronic surface transitions [2]. Additionally, the measurement of Raman spectra for different polarization configurations allows investigating the symmetry of the phonon modes. The comparison of Raman spectra taken at room temperature and low temperatures shows clear differences that can be related to specific structural elements of the surface. This suggests that a structural transition occurred between the two temperatures.
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