Adsorption behavior of 9,9'-Dixanthylidene and moire superstructure on Ru(0001)

This paper reports the adsorption behavior of the 9,9' -Dixanthylidene on Ru(0001), the bottom-up fabrication of graphene is also investigated through a scanning tunneling microscope (STM). We analyze the spatial structure of 9,9'-Dixanthylidene molecules which are randomly dispersed on a Ru(0001) substrate in the sub-monolayer coverage. Then we bottom-up fabricate the graphene on the Ru(0001) substrate with the 9,9'Dixanthylidene molecules as the precursor. Three kinds of moire superstructures with different rotation angles (6.3 degrees, 13.9 degrees, and 16.1 degrees) are found after implementing high temperature annealing in ultrahigh vacuum. This result provides data support for the study of moire superstructures on Ru(0001) substrate and lays a solid foundation for further scientific research based on graphene/Ru(0001).