Regensburg 2010 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 33: Poster II

MA 33.87: Poster

Freitag, 26. März 2010, 11:00–14:00, Poster B1

Examination of spin currents in spin valve structures created by shadow lithography — •Andreas Lörincz¹, Jan Rhensius^{1, 2}, Goran Mihajlović³, Laura Heyderman², Axel Hoffmann³, and Mathias Kläui¹ — ¹Universität Konstanz, 78462 Konstanz, Germany — ²Paul Scherrer Institut, 5232 Villingen, Switzerland — ³Argonne National Laboratory, Argonne, IL 60439-4806, USA

We investigate diffusive spin currents in copper conduits deposited on permalloy halfrings. The main focus on these investigations lies on the comparison with similar samples produced in a two-step lithography method. Structures created by the latter method experience surface oxidation due to exposure to air after the first deposition step, resulting in a contaminated interface. Standard characterizations for the magnetic and spin behaviour, such as GMR, nonlocal spin signal and Hanle measurements are presented in order to determine the differences between both deposition techniques. The effect of diffusive spin currents on magnetic domain walls due to strong surface torques on the magnetization of the affected material is discussed.

Considering the spin diffusion length, we compare these results with measurements on single- or multilayered graphene structures, which are a promising material as a spin conduit in future devices. To take advantage of the high spin diffusion length and the high electron mobility, the main challenge is to effectively inject spins into this two-dimensional conductor. A possible solution are tunnel barriers, which might lead to a larger injection efficiency.