Magnetic properties of intercalated rare-earth metals under graphene*

X-ray magnetic circular dichroism (XMCD) measurements of graphene intercalation with rare-earth metals (REs; Eu, Dy, and Gd) on silicon carbide reveal similar surface magnetic properties in these single layer REs. The intercalation of the REs (Eu, Dy, and Gd) is achieved by depositing the metal on graphene that is grown on SiC and by annealing at high temperatures to allow diffusion through the graphene. STM scans reveal that each of the metals has a distinct nucleation pattern after intercalation, whereby Eu has distinct nano-clusters, Dy has a amorphous clusters, and Gd forms long streaks. Furthermore, the field dependence and temperature dependence of the RE magnetic moments extracted from the XMCD shows paramagnetic behavior, while having a slightly lower moment than predicted by the Brillouin function. We will also provide evidence that the graphene protects these intercalated films by comparing the samples to common oxides and showing the XMCD time dependence after months of exposure to air.