Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 24: Magnetic Heuslers, Half-Metals and Oxides II (organized by MA)

TT 24.6: Vortrag

Montag, 31. März 2014, 16:45–17:00, BEY 118

Direct observation of half metallicity in the Heusler compound Co2MnSi — •Martin Jourdan¹, Alexander Kronenberg¹, Jan Minar², Michaela Kolbe¹, Andrey Gloskovskij³, Gerd Schönhense¹, Hans Joachim Elmers¹, Stanislav Chadov⁴, Claudia Felser⁴, and Mathias Kläui¹ — ¹Institut für Physik, Johannes Gutenberg-Universität Mainz — ²Department Chemie und Biochemie, Ludwig-Maximilians-Universität München — ³Deutsches Elektronen-Synchrotron DESY, Hamburg — ⁴Max-Planck-Institut für Chemische Physik fester Stoffe, Dresden

Heusler compounds are in the focus of interest due to their predicted half-metallic properties, which makes them highly interesting for spintronics. Apart from applications those materials are a test for modern band structure calculations for materials with electronic correlations of medium strength. Although a large body of those calculations is available, their experimental verification remains a major task. Here epitaxial thin films of the compound Co2MnSi are investigated in-situ by UV-photoemission spectroscopy (UPS) taking advantage of a novel multi-channel spin filter. An exceptionally large spin polarization of 93% is obtained at room temperature, providing strong direct evidence for half-metallicity. The energy dependencies of the measured spin polarization as well as of spin integrated UPS essentially agree with bulk band structure calculations. Additional ex-situ spin integrated hard x-ray photoemission spectroscopy experiments (HAXPES) corroborate that indeed bulk states are observed by SRUPS.