Spin current propagation through ultra-thin insulating layers in multilayered ferromagnetic systems

Swindells, C.; Hindmarch, A.T.; Gallant, A.J.; Atkinson, D.

Abstract

Spin current pumping from a ferromagnet through an insulating layer into a heavy metal was studied in a CoFeB/SiO2/Pt system in relation to the thickness and interfacial structure of the insulating layer. The propagation of spin current from the ferromagnet into the heavy metal falls rapidly with sub-nanometer thicknesses of SiO2 and is suppressed beyond a nominal thickness of 2 nm. Structural analysis shows that SiO2 only forms a complete barrier layer beyond around 2 nm, indicating that the presence of a discontinuous insulating barrier, and not tunneling or diffusion, explains the main observations of spin-pumping with thin insulating layers.

Citation

Swindells, C., Hindmarch, A., Gallant, A., & Atkinson, D. (2020). Spin current propagation through ultra-thin insulating layers in multilayered ferromagnetic systems. Applied Physics Letters, 116(4), Article 042403. https://doi.org/10.1063/1.5119787

• Journal Article Type: Article
• Acceptance Date: Jan 17, 2020
• Online Publication Date: Jan 28, 2020
• Publication Date: Jan 28, 2020
• Deposit Date: Jan 31, 2020
• Publicly Available Date: Jan 28, 2021
• Journal: Applied Physics Letters
• Print ISSN: 0003-6951
• Electronic ISSN: 1077-3118
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 116
• Issue: 4
• Article Number: 042403
• DOI: https://doi.org/10.1063/1.5119787
• Public URL: https://durham-repository.worktribe.com/output/1277683