Regensburg 2019 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 31: Spin dynamics: Magnetic relaxation and Gilbert damping

MA 31.2: Vortrag

Mittwoch, 3. April 2019, 12:00–12:15, H52

Two-magnon scattering contribution to damping and its impact in the determination of the spin mixing conductance — •Andres Conca, Sascha Keller, Matthias R. Schweizer, Evangelos Papaioannou, and Burkard Hillebrands — Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany

We present angle dependent measurements of the damping properties of epitaxial Fe layers with MgO, Al and Pt capping layers. Based on the preferential distribution of lattice defects following the crystal symmetry, we make use of a model of the defect density to separate the contribution of two-magnon scattering to the damping from the isotropic contribution originating in the spin pumping effect, the viscous Gilbert damping and the magnetic proximity effect. Without the contribution of the two-magnon scattering, which depends strongly on the chosen capping layer and defect density, a value of the effective spin mixing conductance g_eff^↑↓ is obtained which is closer to the g^↑↓ associated with spin pumping only. The influence of the defect density for bilayers systems due to the different capping layers and to the unavoidable spread in defect density from sample to sample is thus removed. This shows the potential of studying spin pumping phenomena in fully ordered systems in which this separation is possible, contrary to polycrystalline or amorphous metallic thin films.

Financial support by M-era.Net through the HEUMEM project and by the Carl Zeiss Stiftung is gratefully acknowledged.