2018/09/28 by Yan Li, Li, Yan, Yang Li +17
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Properties of Alloys #Magnetic and transport properties of perovskites and related materials #Magnetic properties of thin films #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.1809.11020
openalex publication_date 2018/09/28 · openalex created_date 2018/10/05 · openalex updated_date 2026/07/28
Although both theoretical predications and experimental observations demonstrated that the damping factor is anisotropic at ferromagnet/semiconductor interface with robust interfacial spin-orbit coupling, it is not well understood whether non-local Gilbert damping driven by spin currents in heavy metal/ferromagnetic metal (HM/FM) bilayers is anisotropic or not. Here, we investigated the in-plane angular- and frequency- dependence of magnetic relaxation of epitaxial Fe/MgO(001) films with different capping layers of Pd and Cu. After disentangling the parasitic contributions, such as two-magnon scattering (TMS), mosaicity, and field-dragging effect, we unambiguously observed that both local and non-local Gilbert damping are isotropic in Fe(001) plane, suggesting that the pure spin currents absorption is independent of Fe magnetization orientation in the epitaxial Pd/Fe heterostructure. First principles calculation reveals that the effective spin mixing conductance of Pd/Fe interface is nearly invariant for different magnetization directions in good agreement with the experimental observations. These results offer a valuable insight into the transmission and absorption of pure spin currents, and facilitate us to utilize next-generation spintronic devices.