Dresden 2017 – wissenschaftliches Programm
MA 47.12: Vortrag
Donnerstag, 23. März 2017, 12:30–12:45, HSZ 04
Tuning spin Hall angles by alloying — •S. Wimmer1, K. Chadova1, D. Ködderitzsch1, M. Obstbaum2, M. Decker2, A. K. Greitner2, M. Härtinger2, T. N. G. Meier2, M. Kronseder2, C. H. Back2, and H. Ebert1 — 1Department Chemie, Ludwig-Maximilians-Universität München — 2Institut für Experimentelle und Angewandte Physik, Universität Regensburg
Within a combined experimental and theoretical study it could be shown that the spin Hall angle of a substitutional alloy system can be continuously varied via its composition . For Aux Pt1−x a substantial increase of the maximum spin Hall angle compared to the pure alloy partners could be achieved. The experimental findings for longitudinal charge conductivity σxx, transverse spin Hall conductivity σxyz, and spin Hall angle αSH could be confirmed by calculations based on the Kubo-Bastin formula  implemented in a KKR-CPA framework. Calculations of these response quantities for different temperatures using the so-called Alloy-Analogy Model  show that the divergent behavior of σxx and σxyz is rapidly suppressed with increasing temperature T. As a consequence, σxyz is dominated at higher T by its intrinsic contribution that has only a rather weak temperature dependence. Detailed analysis of the scaling behavior of σxyz(x,T) w.r.t. σxx(x,T) moreover reveals that the extrinsic contribution changes sign as a function of T in the dilute limit x → 0.
 M. Obstbaum et al., Phys. Rev. Lett. 117, 167204 (2016).  A. Bastin et al., J. Phys. Chem. Solids 32, 1811 (1971).  H. Ebert et al., Phys. Rev. B 91, 165132 (2015).