Dresden 2009 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 35: Poster Session II
MM 35.4: Poster
Mittwoch, 25. März 2009, 16:30–18:30, P4
Semiconductor-to-metal transition in FeSi observed using high-resolution photoemission spectroscopy — •Dirk Menzel1, Markus Klein2, Klaus Doll3, Matthias Neef4, Damian Zur1, Ivan Jursic1, Joachim Schoenes1, and Friedrich Reinert2,5 — 1Institut für Physik der Kondensierten Materie, TU Braunschweig, Germany — 2Experimentalphysik II, Universität Würzburg, Germany — 3Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany — 4Institut für Mathematische Physik, TU Braunschweig, Germany — 5FZ Karlsruhe, Gemeinschaftslabor für Nanoanalytik, Germany
High-resolution angle-resolved photoemission spectroscopy was performed on Czochralski-grown FeSi single crystals. Special care was taken during the in-situ preparation of the crystal surface, since the quality and the cleanness of the surface is crucial for the reliability of the obtained photoemission spectra. The experimental data compared to single-particle band structure calculations based on the local density approximation show a strong renormalization of the bands in the vicinity of the Fermi energy due to the self-energy resulting from electronic correlation effects [1]. Temperature dependent photoemission measurements show that the self-energy is strongly k→-dependent at elevated temperatures which is due to scattering of thermally excited charge carriers only at particular crystal momenta. The results obtained by the photoemission investigations evidence that FeSi is not determined by a Kondo scenario but has to be described as a narrow-band semiconductor in which electronic correlations are involved.
[1] M. Klein et al., Phys. Rev. Lett. 101, 046406 (2008).