Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 63: Poster II (Surface Magnetism/ Magnetic Imaging/ Topological Insulators/ Spin Structures and Magnetic Phase Transitions/ Graphene/ Magnetic Thin Films/ Magnetic Semiconductors/ Magnetic Half-metals and Oxides/ Spin-dependent Transport/ Spin Excitations and Spin Torque/ Spin Injection and Spin Currents in Heterostructures/ Spintronics/ Magnetic Storage and Applications)
MA 63.58: Poster
Freitag, 18. März 2011, 11:00–14:00, P2
Element specific magnetic moments and spin-resolved DOS of the half-metallic compounds CoFeMnZ (Z = Al, Ga; Si, Ge) — •Peter Klaer1, Alijani Vajiheh2, Benjamin Balke2, Gerhard H. Fecher2, Claudia Felser2, and Hans-Joachim Elmers1 — 1Institut für Physik, Johannes Gutenberg-Universität, D-55099 Mainz, Germany — 2Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
A new class of materials based on the L21 Heusler crystal structure are quaternary CoFeMnZ (Z = Al, Ga; Si, Ge) alloys. CoFeMnSi with the LiMgPdSb-type structure is predicted to be a half-metallic ferromagnet[1].
We used circular dichroism in x-ray absorption spectroscopy (XMCD) to evaluate the magnetic moments for Co, Fe, and Mn. A comparison with calculations clearly allows to distinguish between various structure models confirming the proposed LiMgPdSb-type structure with predicted half-metallicity. Moreover, we show the element specific spin-resolved unoccupied density of states (DOS) for Co, Fe, and Mn evaluated from XMCD spectra. Exchange of the main group elements from group III (Al, Ga) by those from group IV (Si, Ge) fills majority states and shifts the Fermi energy with respect to the half-metallic band gap in the minority states. The authors are thankful for financial support from the DFG (Grant No. FOR 559).
[1] X. Dai, G. Liu, G. H. Fecher, C. Felser, Y. Li, and H. Liu, J. Appl. Phys., 105, 07E901 (2009).