Berlin 2018 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 23: Non-ultrafast magnetization dynamics
MA 23.6: Vortrag
Mittwoch, 14. März 2018, 10:45–11:00, H 0112
Influence of substrate doping on Spin Pumping — •Babli Bhagat, Tanja Strusch, Michael Farle, and Florian M Römer — Faculty of Physics and Center for Nanointegration (CENIDE), University of Duisburg-Essen, Lotharstr. 1, 47057, Duisburg, Germany
Spin Pumping into semiconductor has a technical as well as fundamental relevance for spintronic devices. The magnetic damping of a Ferromagnet/Semiconductor heterostructure should be influenced by the conductivity and other properties of the semiconductor.
We have studied magnetic damping in Pt/Ag/Fe/GaAs(110) epitaxial heterostructures with different doping of GaAs (undoped, n-doped, and p-doped) by Ferromagnetic Resonance measurements (FMR). Samples were prepared using electron beam evaporation at < 8*10−8 Pa at the rate of ∼1Å/minute. Low Energy Electron Diffraction (LEED) was done before and after depositing epitaxial Fe film on GaAs. Ex situ FMR from 1-40GHz was performed in three different crystallographic directions namely easy <100>, hard <111> and intermediate <110> in plane direction of the film. Also angle dependent FMR at ∼13GHz were performed. The Gilbert-Damping parameter α and anisotropic constants were calculated by fitting frequency dependent and angle dependent lineshape respectively. We observed different damping behaviour at different directions of the film. With respect to undoped sample there is ∼15% increase in α in hard <111> direction in p-doped sample while ∼12% increase in <110> direction. In easy direction there is instead ∼28% decrease of damping parameter with undoped sample in p-doped GaAs.