Berlin 2015 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 20: POSTER Ib

MA 20.14: Poster

Dienstag, 17. März 2015, 09:30–13:00, Poster A

Spin pumping by magnetization precession in a wide frequency range — •Viktor Lauer, Thomas Brächer, Burkard Hillebrands, and Andrii Chumak — Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaisterslautern, Germany

Spin pumping refers to the spin-current generation in a normal metal film caused by the magnetization precession in an attached magnetic film. Via the inverse spin Hall effect (ISHE) this spin current is transformed into a conventional charge current.

Various parameters influence the spin-pumping induced ISHE voltage and require experimental analysis in order to understand the physical principles behind. In our study we address the dependence of spin pumping on the frequency of the magnetization precession, for frequencies 1-45 GHz. Our spin-pumping experiments were performed on a YIG(100nm)|Pt(10nm) bi-layer system. Theoretical predictions show that the generated voltage should decrease monotonically with increase in frequency. However, we observe a more complex ISHE voltage dependence on frequency, that exhibits a pronounced maximum at 11 GHz. The behaviour above 11 GHz qualitatively agrees with theoretical predictions. The deviation from theory below 11 GHz may be due to the frequency dependent excitation efficiency because of the precession ellipticity, as well as due to the change of pinning conditions by the external magnetic field.