Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 32: Postersession II: Spinstruct./Phase Trans. (1-10); Spinelectronics (11-15); Thin Films (16 - 36); Particles/Clusters (37-45); Multiferroics (46-54); Spindynamics/Spin Torque (55 - 76); Post Deadlines (77-79)

MA 32.55: Poster

Freitag, 29. Februar 2008, 11:15–14:00, Poster E

Current and Field Induced Domain-Wall Motion in Permalloy Nanowires — •Gesche Nahrwold, Lars Bocklage, Hannah Ziehlke, Toru Matsuyama, Ulrich Merkt, and Guido Meier — Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg

Magnetic domain walls in nanowires have attracted a lot of interest because of their possible application in logic and memory devices. A novel concept is based on electric currents that push magnetic domain walls along nanowires. This motion can be detected by measuring the anisotropic magnetoresistance (AMR)[1]. We present results obtained in curved permalloy wires where domain walls are pushed by current pulses with durations in the nanosecond range. By an externally applied magnetic field the domain wall is induced at a well defined position in the curved region of the wire. Measurements of the AMR verify the presence of the walls. The resistance values before and after a current pulse indicate whether the domain wall has been depinned and moved out of the wire or not. We observe a strong dependence of the depinning efficiency on the pulse length with a threshold of 1 ns. We found indications that deposition at elevated substrate temperatures is promising to attain a higher quality of the permalloy which is essential to avoid unwanted pinning centres for domain walls. Films sputtered at 400 °C have a dramatically smaller specific resistance compared with those sputtered at room temperature. [1] L. Thomas, M. Hayashi, X. Jiang, R. Moriya, C. Rettner, and S. S. P. Parkin, Nature 443, 197 (2006).