▎ 摘　　要

The Pb intercalation at the interface of monolayer graphene (MG) and Ru(0001) is studied by means of low temperature scanning tunneling microscopy (LT-STM) and Raman spectroscopy. Despite being covered by MG, the atomic structures of the Pb layer formed between MG and Ru(0001) have been directly imaged using LT-STM. The Pb layer intercalated underneath MG exhibits a root 7 x root 7-R19 degrees superstructure with respect to the Ru(0001) surface. STM and Raman spectroscopy measurements and density functional theory calculations reveal that the epitaxial MG are effectively decoupled from the Ru(0001) substrate and recover its intrinsic electronic property after Pb intercalation.