Harnessing the Graphene/Pt/FM Interface for Improved Spin-To-Charge Current Conversion

The use of graphene in spintronic devices is contingent on its ability to convert a spin current to a charge current. We have systematically investigated the spin-pumping-induced spin-to-charge current conversion at the graphene/FM interface and the effect of interface modification through high spin–orbit coupling (SOC) material (Pt) as an interlayer (IL) of varying thicknesses by using broadband FMR spectroscopy. The spin-mixing conductance is enhanced from 1.66 × 10 18 m –2 to 2.72 × 10 18 m –2 while the spin current density is enhanced from 0.135 ± 0.003 to 0.242 ± 0.004 MA/m 2 at the graphene/FM interface due to interface modification using high SOC material Pt(1,2 nm) as an interlayer. The spin-to-charge current conversion efficiency for the graphene/FM interface is found to be ≈0.003 nm but increases to ≈0.039 nm for the SLG/Pt(1 nm)/FM interface and to ≈0.062 nm for the SLG/Pt(2 nm)/FM interface. . These findings support the idea that graphene in combination with a high SOC material (Pt) could be a potential candidate for spintronic applications, specifically for spin-torque-based memory applications.