Regensburg 2016 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 44: Spininjection / Spin currents in heterostructures

MA 44.4: Vortrag

Donnerstag, 10. März 2016, 15:45–16:00, H31

Skew-scattering Anomalous and Spin Hall effects in L1₀-ordered FePt alloys — •Bernd Zimmermann, Nguyen H. Long, Phivos Mavropoulos, Stefan Blügel, and Yuriy Mokrousov — Peter Grünberg Institut & Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

The Spin Hall effect (SHE) and inverse SHE are of fundamental importance for spinorbitronics, as they are the main source of spin current generation and detection. Intimately related is the anomalous Hall effect (AHE), which in addition appears in magnetic materials. New insights into the common underlying mechanisms can be anticipated from a combined study of both. Here, we turn our attention to the L1₀-ordered FePt alloy and determine by ab-initio calculations the disorder-induced skew-scattering contribution to AHE and SHE. We investigate the role of different antisite-defects, such as Pt atoms occupying Fe sites (and vice versa) where the stoichiometry deviates from the 1:1 ratio, or where the ideal stoichiometry remains but nearest-neighbor Fe and Pt atoms switch sites and form a dimer. Our results reveal that Fe-antisite defects show the largest Hall angles of about 1%, which is of the same order of magnitude as experimentally measured Hall angles [1]. On the contrary, Hall angles for Pt-antisite defects are smaller in magnitude and of different sign. As we show, the effect of FePt-dimers can only be addressed by explicit ab-initio calculations, while the approximative Matthiessen rule greatly fails.

[1] K.M. Seemann et al., Phys. Rev. Lett. 104, 076402 (2010).