Study of Spin-Orbit Interactions and Interlayer Ferromagnetic Coupling in Co/Pt/Co Trilayers in Wide Range of Heavy Metal Thickness

Piotr Ogrodnik; Krzysztof Grochot; Łukasz Karwacki; Jarosław Kanak; Michał Prokop; Jakub Chęciński; Witold Skowroński; Sławomir Ziętek; Tomasz Stobiecki

arXiv · 2106.10103

Study of Spin-Orbit Interactions and Interlayer Ferromagnetic Coupling in Co/Pt/Co Trilayers in Wide Range of Heavy Metal Thickness

Piotr Ogrodnik·Krzysztof Grochot·Łukasz Karwacki·Jarosław Kanak·Michał Prokop·Jakub Chęciński·Witold Skowroński·Sławomir Ziętek·Tomasz Stobiecki

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Abstract

The spin-orbit torque, a torque induced by a charge current flowing through the heavy-metal conducting layer with strong spin-orbit interactions, provides an efficient way to control the magnetization direction in heavy-metal/ferromagnet nanostructures, required for applications in the emergent magnetic technologies like random access memories, high-frequency nano oscillators, or bio-inspired neuromorphic computations. We study the interface properties, magnetization dynamics, magnetostatic features and spin-orbit interactions within the multilayer system Ti(2)/Co(1)/Pt(0-4)/Co(1)/MgO(2)/Ti(2) (thicknesses in nanometers) patterned by optical lithography on micrometer-sized bars. In the investigated devices, Pt is used as a source of the spin current and as a non-magnetic spacer with variable thickness, which enables the magnitude of the interlayer ferromagnetic exchange coupling to be effectively tuned. We also find the Pt thickness-dependent changes in magnetic anisotropies, magnetoresistance, effective Hall angle and, eventually, spin-orbit torque fields at interfaces. The experimental findings are supported by the relevant interface structure-related simulations, micromagnetic, macrospin, as well as the spin drift-diffusion models. Finally, the contribution of the spin-orbital Edelstein-Rashba interfacial fields is also briefly discussed in the analysis.

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Piotr Ogrodnik, Krzysztof Grochot, Łukasz Karwacki, Jarosław Kanak, Michał Prokop, Jakub Chęciński, Witold Skowroński, Sławomir Ziętek, Tomasz Stobiecki. 2021-06-18. Study of Spin-Orbit Interactions and Interlayer Ferromagnetic Coupling in Co/Pt/Co Trilayers in Wide Range of Heavy Metal Thickness. https://arxiv.org/abs/2106.10103

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