2018/02/19 by Yongxi Ou, D. C. Ralph, R. A. Buhrman · 59 citations
Materials Science · Mathematics · Physics and Astronomy · #Condensed matter physics #Curie #Curie temperature #Ferromagnetism #Magnetic Properties and Applications #Magnetic properties of thin films #Mathematics #Physics #Point (geometry) #Quantum and electron transport phenomena #Spin (aerodynamics) #Thermodynamics #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.120.097203
published in Physical Review Letters 120(9), 097203 (American Physical Society) · 23 pages, 4 figures. Accepted in Physical Review Letters
arxiv created 2018/02/19 · openalex publication_date 2018/03/01 · arxiv updated 2018/03/05 · openalex created_date 2018/03/06 · openalex updated_date 2026/08/06
Robust spin Hall effects (SHE) have recently been observed in nonmagnetic heavy metal systems with strong spin-orbit interactions. These SHE are either attributed to an intrinsic band-structure effect or to extrinsic spin-dependent scattering from impurities, namely, side jump or skew scattering. Here we report on an extraordinarily strong spin Hall effect, attributable to spin fluctuations, in ferromagnetic FexPt1-x alloys near their Curie point, tunable with x. This results in a dampinglike spin-orbit torque being exerted on an adjacent ferromagnetic layer that is strongly temperature dependent in this transition region, with a peak value that indicates a lower bound 0.34±0.02 for the peak spin Hall ratio within the FePt. We also observe a pronounced peak in the effective spin-mixing conductance of the FM/FePt interface, and determine the spin diffusion length in these FexPt1-x alloys. These results establish new opportunities for fundamental studies of spin dynamics and transport in ferromagnetic systems with strong spin fluctuations, and a new pathway for efficiently generating strong spin currents for applications.