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O: Fachverband Oberflächenphysik

O 34: Poster Session I (Graphene; Plasmonics and nanooptics; Coherence and coherent control in nanophotonics and plasmonics)

O 34.1: Poster

Tuesday, March 27, 2012, 18:15–21:45, Poster E

Oxidation of monovacancies in graphene by oxygen molecules — •Udo Schwingenschlögl, Thaneshwor Kaloni, and Yingchun Cheng — KAUST, PSE Division, 23955-6900 Thuwal, Kingdom of Saudi Arabia

We study the local magnetic moments develop at monovacancies in graphene due to the presence of dangling carbon bonds. These moments remain intact when an oxygen molecule is adsorbed such that the dangling bonds are not fully saturated. We obtain values of 1.35 and 1.86 µ_B for the magnetic moments of monovacancies and oxidized monovacancies, respectively. A transition from semimetallic to semiconducting behavior appears if at least one C–O–C bridge is present, whereas the formation of C=O groups makes the system metallic. Our results explain the experimentally observed behavior of graphene under exposure to an oxygen plasma.

Reference: J. Mater. Chem. 21, 18284 (2011).