Theory of Spin Hall Effect in Random Pt-M (M = V, Nb, Ta) Alloys

I. Tureka, J. Kudrnovskýb, V. Drchalb aInstitute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, 61662 Brno, Czech Republic bInstitute of Physics, Czech Academy of Sciences, Na Slovance 2, 18221 Praha, Czech Republic

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The spin Hall effect in fcc Pt-rich disordered solid solutions Pt-M (M = V, Nb, Ta) is studied by means of a relativistic ab initio Green-function theory. We find that the spin Hall angle of all three alloy systems exhibits similar sizable values, with a maximum slightly above 0.2, obtained for dopant concentrations around 12 at.%. This result is explained by a competition between opposite concentration trends of the intrinsic spin Hall conductivity and of the longitudinal residual resistivity while the strength of the impurity spin-orbit interaction plays only a minor role. This behavior agrees qualitatively with results of recent experiments on spin Hall torques in multilayered systems involving Pt-rich alloys with heavy and light impurities.

DOI:10.12693/APhysPolA.137.717 topics: spin Hall effect, ab initio theory, random alloys