Intercalated europium metal in epitaxial graphene on SiC

X-ray magnetic circular dichroism (XMCD) reveals the magnetic properties of intercalated europium metal under graphene on SiC(0001). The intercalation of Eu nanoclusters (average size 2.5 nm) between graphene and SiC substate are formed by deposition of Eu on epitaxially grown graphene that is subsequently annealed at various temperatures while keeping the integrity of the graphene layer. Using sum-rules analysis of the XMCD of Eu M-4,M-5 edges at T = 15 K, our samples show paramagnetic-like behavior with distinct anomaly at T approximate to 90 K, which may be related to the Neel transition, T-N = 91 K, of bulk metal Eu. We find no evidence of ferromagnetism due to EuO or antiferromagnetism due to Eu2O3, indicating that the graphene layer protects the intercalated metallic Eu against oxidation over months of exposure to atmospheric environment.