Discovering graphene’s ferromagnetic phase

Scientists at Diamond Light Source have explored the interface between iron and graphene, with findings that illuminate the prospect of graphene-based transistors. Results published in Scientific Reports suggest a well-maintained ferromagnetic order of the interface up to room temperature. Furthermore, the researchers have observed reduced magnetic moments of the epitaxial iron (the crystalline overlayer covering the graphene) compared to iron in its normal bulk state. Yet the magnetism observed was still sizable enough to indicate its potential for spintronic applications.

Successful spin injection into graphene would make it a key contender in the race to develop materials suitable for quantum computing, and the junction between a layer of graphene and a layer of iron presents a potential avenue to be exploited. However, the magnetism at this interface is not well understood. The X-ray magnetic circular dichroism (XMCD) technique afforded by the I10 beamline ‘BLADE’ (Beamline for Advanced Dichroism Experiments) is one of the most powerful tools on offer to explore the surface/interface magnetic and chemical properties. The researchers from the University of York, University of Science and Technology of China, the Renmin University of China, and Diamond were able to observe a suppression of the Fe magnetisation caused by a hybridisation between the Fe and C orbitals, which led to an sp-orbital-like behaviour of the Fe 3d electrons due to the presence of the graphene.

Strong support for fundamental physics