▎ 摘　　要

Intercalation of Pb at graphene/Ru(0001) interfaces has been dynamically observed using in situ low energy electron microscopy and photoemission electron microscopy. A comparative study of Pb intercalation on the submonolayer and complete monolayer graphene surfaces suggest that the Pb intercalation happens through the open edges of graphene islands, starting at around 150 degrees C. Spatially-resolved low energy electron diffraction measurements reveal that the Pb-intercalated graphene overlayers are quasi-free-standing. The intercalated graphene sheets show lower reactivity to oxidation in O-2.