Oxidation of graphene on Ru(0 0 0 1) studied by scanning tunneling microscopy

• Published in: Applied surface science 2010-10, Vol.257 (1), p.82-86
• Main Authors: Liao, Q., Zhang, H.J., Wu, K., Li, H.Y., Bao, S.N., He, P.
• Format: Article
• Language: English
• Subjects: Atomic oxygen; Carbon; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; Graphene/Ru; Intercalation; Lattices; Materials science; Methods of nanofabrication; Moire patterns; Nanooxidation; Oxidation; Physics; Scanning tunneling microscopy; Specific materials; Superstructures; Surface treatments
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2010.06.037

The oxidation of graphene layer on Ru(0 0 0 1) has been investigated by means of scanning tunneling microscopy. Graphene overlayer can be formed by decomposing ethyne on Ru(0 0 0 1) at a temperature of about 1000 K. The lattice mismatch between the graphene overlayer and the substrate causes a moiré pattern with a superstructure in a periodicity of about 30 Å. The oxidation of graphene/Ru(0 0 0 1) was performed by exposure the sample to O 2 gas at 823 K. The results showed that, at the initial stage, the oxygen intercalation between the graphene and the Ru(0 0 0 1) substrate takes place at step edges, and extends on the lower steps. The oxygen intercalation decouples the graphene layer from the Ru(0 0 0 1) substrate. More oxygen intercalation yields wrinkled bumps on the graphene surface. The oxidation of graphene, or the removal of carbon atoms can be attributed to a process of the combination of the carbon atoms with atomic oxygen to form volatile reaction products. Finally, the Ru(0 0 0 1)–(2 × 1)O phase was observed after the graphene layer is fully removed by oxidation.