High spin polarization and spin signal enhancement in non-local spin valves with Co–Fe alloy injectors and detectors

Autor: B. Kaiser, J. Ramberger, J. D. Watts, J. Dewey, Y. Zhang, C. Leighton
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: APL Materials, Vol 11, Iss 5, Pp 051108-051108-8 (2023)
Druh dokumentu: article
ISSN: 2166-532X
DOI: 10.1063/5.0147465
Popis: For applications such as spin accumulation sensors for next-generation hard disk drive read heads, and for fundamental research, it is desirable to increase the spin signal in metallic non-local spin valves, which are central devices in spintronics. To this end, here, we report on the integration of high-spin-polarization Co–Fe binary alloy ferromagnetic injectors and detectors in Al-based non-local spin valves. Room-temperature deposition on amorphous substrates from an alloy target is shown to generate smooth, polycrystalline (110-textured), solid-solution body-centered-cubic Co75Fe25 films, which we characterize by energy dispersive x-ray spectroscopy, x-ray diffraction, x-ray reflectivity, atomic force microscopy, and electronic transport. Simple integration into transparent-interface Al non-local spin valves is then shown to realize up to a factor of ∼5 enhancement of the spin signal relative to Co, with full quantitative analysis yielding strikingly temperature-independent current spin polarizations exceeding 60%. We make a detailed quantitative comparison of these values with prior literature, concluding that Co–Fe alloys present a remarkably facile route to higher spin polarization and spin signals in non-local spin valves, with minimal barrier to adoption.
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