Dresden 2011 – wissenschaftliches Programm

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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 63.79: Poster

Freitag, 18. März 2011, 11:00–14:00, P2

The influence of multi-layer structure of Heusler compound electrodes on transport properties and magnon excitation of magnetic tunnel junctions — •Volker Drewello, Daniel Ebke, Markus Schäfers, Günter Reiss, and Andy Thomas — Bielefeld University, Bielefeld, Germany

Magnetic tunnel junctions with single layers and multilayers of the Heusler compounds Co₂FeAl, Co₂FeSi, and Co₂MnSi as the soft magnetic electrode are prepared. Pinned Co-Fe is used as the hard reference electrode. The junctions show a high tunnel magnetoresistance ratio up to 331 % at 13 K. The electronic transport characteristics are investigated by tunneling spectroscopy. The spectra of the different samples are compared by normalized IETS. The multilayered electrodes show unique influence on the spectra in the parallel state, and when tunneling out of the Heusler. In the other cases (antiparallel state, or tunneling into the Heusler) a hugh contribution prevails, which we identify as magnon excitation. A comparison to the temperature dependence of the TMR ratio is drawn.