Electrical measurement of the spin Hall effect isotropy in ferromagnets with strong spin-orbit interactions

Abstract

The spin-dependent transport properties of paramagnetic metals are roughly invariant under rotation. By contrast, in ferromagnetic materials, the magnetization breaks the rotational symmetry, and, thus, the spin Hall effect is expected to become anisotropic. Here, using a specific design of lateral spin valves, we measure electrically the spin Hall effect anisotropy in ferromagnetic NiCu and NiPd. We show that the magnetization vector does not lead to a sizable anisotropy of the spin charge interconversion and spin transport parameters in materials with a spin-orbit coupling comparable to the exchange interaction.