Studies on Magnetism of Transition Metal Layers Grown on Graphene

Magnetism of organic molecules and carbon atoms has attracted much attention. Among these materials, graphene, a single layer of carbon atoms, has been investigated intensively. Theoretical studies on transition metal induced magnetism of graphene has been developed for years[1] [2], while growing such homogeneous thin film experimentally remains challenging. On the other hand, intercalation of cobalt through graphene has shown relatively strong ferromagnetism in cobalt, and anti-ferromagnetism in carbon, which is a candidate of layered magnetic material[3]. Here we report our studies on the magnetism of Fe, Co, or Ni thin film deposited on graphene. The graphene sheet was grown via chemical vapor deposition (CVD) on a Pt(111) substrate, which is known to have weak coupling with graphene[4] and form graphene without a certain orientation (Fig. 1). The magnetism was checked via MOKE and XMCD. The as-grown metal layers on graphene only showed in-plane magnetism at above 20ML (Fig. 2), and no significant magnetism of carbon was found. Sub-monolayer of Fe/Co/Ni intercalated under graphene remains for the future work.