X-ray spectroscopy of current-induced spin-orbit torques and spin accumulation in Pt/3d transition metal bilayers

Abstract

An electric current flowing in Pt, a material with strong spin-orbit coupling, leads to spins accumulating at the interfaces by virtue of the spin Hall effect and interfacial charge-spin conversion. We measure the influence of these interfacial magnetic moments onto adjacent 3d transition metal layers by x-ray absorption spectroscopy and x-ray magnetic circular dichroism in a quantitative and element-selective way, with sensitivity below $10^{-5}{\mu }_B$ per atom. In Pt(6 nm)/Co(2.5 nm), the accumulated spins cause a deviation of the Co magnetization direction, which corresponds to an effective spin-Hall angle of 0.08. The spin and orbital magnetic moments of Co are affected in equal proportion by the absorption of the spin current, showing that the transfer of orbital momentum from the recently predicted orbital Hall effect is either below our detection limit, or not directed to the 3d states of Co. For Pt/NM (NM = Ti, Cr, Cu), we find upper limits for the amount of injected spins corresponding to about $3\times 10^{-6}{\mu }_B$ per atom.

References in corpus (20)

• Spin Torque Ferromagnetic Resonance Induced by the Spin Hall Effect
• Direct electronic measurement of the spin Hall effect
• Symmetry and magnitude of spin-orbit torques in ferromagnetic heterostructures
• Layer thickness dependence of the current induced effective field vector in Ta|CoFeB|MgO
• Quantitative characterization of the spin orbit torque using harmonic Hall voltage measurements
• Current induced torques and interfacial spin-orbit coupling: Semiclassical Modeling
• Spin torque study of the spin Hall conductivity and spin diffusion length in platinum thin films with varying resistivity
• Interplay of spin-orbit torque and thermoelectric effects in ferromagnet/normal metal bilayers
• Intrinsic Spin and Orbital Hall Effects from Orbital Texture
• Unidirectional spin Hall magnetoresistance in ferromagnet/normal metal bilayers
• Giant Orbital Hall Effect in Transition Metals: Origin of Large Spin and Anomalous Hall Effects
• Tuning the spin Hall effect of Pt from the moderately dirty to the superclean regime
• Time- and spatially-resolved magnetization dynamics driven by spin-orbit torques
• Gigantic intrinsic orbital Hall effects in weakly spin-orbit coupled metals
• Thickness dependence of the resistivity of Platinum group metal thin films
• Magneto-Optical Detection of the Spin Hall Effect in Pt and W Thin Films
• Investigation of induced Pt magnetic polarization in Pt/Y3Fe5O12 bilayers
• Reciprocal spin Hall effects in conductors with strong spin-orbit coupling: a review
• X-Ray Detection of Transient Magnetic Moments Induced by a Spin Current in Cu
• Imaging of lateral spin valves with soft X-ray microscopy

Cited by in corpus (6)

• Orbitronics: Orbital Currents in Solids
• Quantitative comparison of electrically induced spin and orbital polarizations in heavy-metal/3d-metal bilayers
• Hidden interplay of current-induced spin and orbital torques in bulk Fe${}_3$GeTe${}_2$
• First principles calculations of steady-state voltage-controlled magnetism: application to x-ray absorption spectroscopy experiment
• Electronic Impurity Scattering Induced Spin Accumulation in Metallic Thin Films
• Orbital Dynamics in Centrosymmetric Systems