Spin-to-charge conversion by spin pumping in sputtered polycrystalline Bi${}_x$Se${}_{1-x}$

Abstract

Topological materials are of high interest due to the promise to obtain low power and fast memory devices based on efficient spin-orbit torque switching or spin-orbit magnetic state read-out. In particular, sputtered polycrystalline Bi${}_x$Se${}_{1-x}$ is one of the materials with more potential for this purpose since it is relatively easy to fabricate and has been reported to have a very high spin Hall angle. We study the spin-to-charge conversion in Bi${}_x$Se${}_{1-x}$ using the spin pumping technique coming from the ferromagnetic resonance in a contiguous permalloy thin film. We put a special emphasis on the interfacial properties of the system. Our results show that the spin Hall angle of Bi${}_x$Se${}_{1-x}$ has an opposite sign to the one of Pt. The charge current arising from the spin-to-charge conversion is, in contrast, lower than Pt by more than one order of magnitude. We ascribe this to the interdiffusion of Bi${}_x$Se${}_{1-x}$ and permalloy and the changes in chemical composition produced by this effect, which is an intrinsic characteristic of the system and is not considered in many other studies.

References in corpus (8)

• Room-Temperature Quantum Hall Effect in Graphene
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• Surface state dominated spin-charge current conversion in topological insulator/ferromagnetic insulator heterostructures
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• Measurement of spin pumping voltage separated from extrinsic microwave effects
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• All-electrical spin-to-charge conversion in sputtered Bi${}_x$Se${}_{1-x}$
• Thermal spin current generation in the multifunctional ferrimagnet Ga${}_{0.6}$Fe${}_{1.4}$O${}_3$

Cited by in corpus (5)

• Giant and anisotropic enhancement of spin-charge conversion in double Rashba interface graphene-based quantum system
• Quantification of spin-charge interconversion in highly resistive sputtered Bi${}_x$Se${}_{1-x}$ with non-local spin valves
• Self-induced spin pumping and inverse spin Hall effect in single FePt thin films
• Temperature dependent spin dynamics in La${}_{0.67}$Sr${}_{0.33}$MnO${}_3$/Pt bilayers
• RF field characterization and rectification effects in spin pumping and spin-torque FMR for spin-orbitronics