title: Direct observation of half-metallicity in the Heusler compound Co2MnSi.
abstract: Ferromagnetic thin films of Heusler compounds are highly relevant for spintronic applications owing to their predicted half-metallicity, that is, 100% spin polarization at the Fermi energy. However, experimental evidence for this property is scarce. Here we investigate epitaxial thin films of the compound Co2MnSi in situ by ultraviolet-photoemission spectroscopy, taking advantage of a novel multi-channel spin filter. By this surface sensitive method, an exceptionally large spin polarization of (93(-11)(+7)) % at room temperature is observed directly. As a more bulk sensitive method, additional ex situ spin-integrated high energy X-ray photoemission spectroscopy experiments are performed. All experimental results are compared with advanced band structure and photoemission calculations which include surface effects. Excellent agreement is obtained with calculations, which show a highly spin polarized bulk-like surface resonance ingrained in a half metallic bulk band structure.
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, 55128 Mainz, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Jourdan
authors.affiliation: 1] Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 11, 81377 München, Germany [2] New Technologies-Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Minár
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 11, 81377 München, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Braun
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, 55128 Mainz, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kronenberg
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Chadov
authors.affiliation: Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Staudingerweg 9, 55128 Mainz, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Balke
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Gloskovskii
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, 55128 Mainz, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kolbe
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, 55128 Mainz, Germany.
authors.forename: H J
authors.initials: HJ
authors.lastname: Elmers
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, 55128 Mainz, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Schönhense
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 11, 81377 München, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Ebert
authors.affiliation: 1] Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany [2] Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität, Staudingerweg 9, 55128 Mainz, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Felser
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität, Staudingerweg 7, 55128 Mainz, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kläui