Graphene/Rh(111) Structure Studied Using In-Situ Scanning Tunneling Microscopy**Supported by the National Natural Science Foundation of China under Grant No 51402026, the Basic Research Program of Jiangsu Province under Grant No BK20130236, and the High Technology Research Key Laboratory of Changzhou under Grant No CM20133007.

Abstract

Scanning tunnel microscopy (STM) is performed to verify if an Rh ‘nails’ structure is formed accompanying the graphene growing during chemical vapor deposition. A structure of a graphene island in an Rh vacancy island is used as the start. While the graphene island is removed by oxygenation, the variations of the Rh vacancy island are imaged with an in-situ high-temperature STM. By fitting with our model and calculations, we conclude that the best fit is obtained for 0% Rh, i.e., for the complete absence of nails below graphene on Rh(111). That is, when graphene is formed on Rh(111), the substrate remains flat and does not develop a supporting nail structure.