Reduced spin-Hall effects from magnetic proximity

Harnessing spin-orbit coupling for the manipulation of spins and magnetization via electric charge currents is the key objective of spin-orbitronics. Towards this end ferromagnetic materials are combined with nonmagnetic materials with strong spin-orbit coupling (typically involving heavy elements). However, many of the nominally nonmagnetic materials are highly susceptible to magnetic proximity effects, and the role of induced moments for spin transport has been controversial. Here we demonstrate that for Pt and Pd increased induced magnetic moments are correlated with strongly reduced spin-Hall conductivities. This observation finds an intuitive explanation in the development of a spin splitting of the chemical potential and the energy dependence of the intrinsic spin-Hall effect determined by first-principles calculations. This work provides simple guidance towards the optimization of spin current efficiencies for devices based on spin-orbit coupling phenomena.