Dresden 2009 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 37: Transport: Nanoelectronics II - Spintronics and Magnetotransport

TT 37.7: Vortrag

Donnerstag, 26. März 2009, 11:00–11:15, HSZ 105

Anisotropy of the intrinsic anomalous Hall effect in FePt, FePd and FeNi ordered alloys — •Yuriy Mokrousov^1,2, Eric Roman¹, and Ivo Souza¹ — ¹University of California at Berkeley, USA — ²Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich, Germany

We calculate from first principles the intrinsic anomalous Hall conductivity (AHC) of the layered L1₀ alloys FePt, FePd and FeNi. We find large intrinsic contributions (comparable to those of bulk Fe, Co, and Ni), in apparent disagreement with a recent experimental work (K.M. Seemann et al., arXiv:0811.1258) which attributed the anomalous Hall effect in FePd and FePt entirely to skew-scattering from impurities. We propose that a clear signature of the intrinsic effect in these materials is its strong dependence on the orientation of the magnetization with respect to the uniaxial direction, while skew-scattering is expected to be largely isotropic. The calculated anisotropy has opposite signs for FePt (where the AHC is reduced by almost a factor of two as the magnetization direction is changed from the [001] to the [110] direction) and for FePd and FeNi, where instead it increases, but by a smaller amount. By selectively turning off the spin-orbit interaction on the Fe and X atoms (X=Pt,Pd,Ni), we investigate their individual contributions to the AHC.