2016/07/31 by Pablo Aßhoff, P. U. Asshoff, J. L. Sambricio +19 · 106 citations
Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #Advancements in Battery Materials #Biasing #Condensed matter physics #Electron #Ferromagnetism #Graphene #Graphene nanoribbons #Graphene research and applications #Magnetic field #Magnetism #Magnetoresistance #Materials science #Nanotechnology #Physics #Spin Hall effect #Spin polarization #Spin pumping #Spintronics #Voltage #cond-mat.mes-hall
paper · pdf · doi:10.1088/2053-1583/aa7452
published in 2D Materials 4(3), 031004 (IOP Publishing) · 12 pages, 6 figures, Supplementary Information (6 Supplementary Notes, 11 supplementary figures)
openalex publication_date 2017/05/19 · arxiv created 2017/06/16 · arxiv updated 2018/01/03 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
Graphene is hailed as an ideal material for spintronics due to weak intrinsic spin–orbit interaction that facilitates lateral spin transport and tunability of its electronic properties, including a possibility to induce magnetism in graphene. Another promising application of graphene is related to its use as a spacer separating ferromagnetic metals (FMs) in vertical magnetoresistive devices, the most prominent class of spintronic devices widely used as magnetic sensors. In particular, few-layer graphene was predicted to act as a perfect spin filter. Here we show that the role of graphene in such devices (at least in the absence of epitaxial alignment between graphene and the FMs) is different and determined by proximity-induced spin splitting and charge transfer with adjacent ferromagnetic metals, making graphene a weak FM electrode rather than a spin filter. To this end, we report observations of magnetoresistance (MR) in vertical Co-graphene-NiFe junctions with 1–4 graphene layers separating the ferromagnets, and demonstrate that the dependence of the MR sign on the number of layers and its inversion at relatively small bias voltages is consistent with spin transport between weakly doped and differently spin-polarized layers of graphene. The proposed interpretation is supported by the observation of an MR sign reversal in biased Co-graphene-hBN-NiFe devices and by comprehensive structural characterization. Our results suggest a new architecture for vertical devices with electrically controlled MR.