In ferromagnet/heavy metal bilayers, a spin current can be generated under the ferromagnetic resonance (FMR) condition, and then converted into a charge current in adjacent nonmagnetic metals through inverse spin Hall effect (ISHE).

CSNS researchers report an experimental observation of interface induced ISHE enhancement in NiFe/Pt bilayers covered by MgO layer. Compared to bare NiFe/Pt bilayers, Pt/MgO interface induces an enhancement of the spin-charge conversion in the NiFe/Pt/MgO trilayers with very thin Pt layers, in agreement with the corresponding trend of Gilbert damping enhancement. When the thickness of Pt is below 1.6 nm, the ISHE induced charge current has about 70% enhancement. These results open a new pathway to improve the spin-charge conversion efficiency by interface engineering.

ISHE measurements were performed to investigate MgO capping layer effect on spin-charge conversion in NiFe/Pt bilayers. Compared to bare NiFe/Pt with thin Pt layer, an enhancement of spin-charge conversion is observed in the NiFe/Pt/MgO trilayers, in consistent with the additional enhancement of Gilbert damping from FMR measurements. When thickness of Pt is below 1.6 nm, the ISHE induced charge current has about 70% enhancement.

These results demonstrate an experimental approach for a high interface SHE due to the surface modification.

The full publication can be found here: https://iopscience.iop.org/article/10.1088/1361-648X/ab172a