Observation of Mg-induced structural and electronic properties of graphene

We report the formation of superstructures induced byMg adatoms on a single layergraphene (SLG) formed on Ni(111) substrate, where a strong metallic parabolic band is found near the Fermi level at the Γ-point of the Brillouin zone. Our valence band and core level data obtained by using synchrotron photons indicate thatMg adatoms intercalate initially to lift the SLG from theNi substrate to produce a well-defined π-band of SLG, and then the parabolic band appears upon adding extraMg atoms on the Mg-intercalated SLG. Ourscanning tunneling microscopy images from these systems show the presence of superstructures, a 2 √3 × 2√3 phase for the intercalatedMg layer below the SLG and then a √7 × √7 phase for theMg overlayer formed on the Mg-intercalated SLG. We discuss the physical implications of these superstructures and the associated parabolic band in terms of a possible graphene-based two-dimensionalsuperconductivity.

Source: Applied Physics Letters - November 7, 2016 Category: Physics Authors: Heemin Park, Laishram Tomba Singh, Paengro Lee, Jingul Kim, Mintae Ryu, Chan-Cuk Hwang, Kwang S. Kim and Jinwook Chung Source Type: research