Probing the Spin Orbit Coupling in Metal-Molecular Interfaces

This proposal aims to unravel spin scattering mechanisms in metal-molecular interfaces with high spin orbit coupling (SOC) materials. Effects based on the SOC have attracted wide attention due to their application in spin orbit torque memories, energy generation and other applications. Molecular interfaces can be used to tune or enhance these effects. Charge transfer and orbital rehybridisation lead to conducting states in the carbon material. We have observed that this hybridised layer leads to enhanced SOC and spin conversion effects, for example by increasing the spin Hall and anisotropic magnetoresistance of YIG/Pt and YIG/Ta wires with a fullerene over layer [1]. DFT modelling of these structures shows an enhanced acquired moment in the conduction metal electrons in the presence of the molecules. We propose to probe the spin physics in metallo-molecular interfaces on ferrimagnetic substrates via NEXAFS and XMCD, which we have successfully used in past beamtimes to demonstrate the emergence of magnetic ordering [2,3] and spin capacitance at molecular interfaces [4].