Record number :
1000621
Title of article :
Scanning tunneling microscopy and spectroscopy studies of graphite edges
Author/Authors :
Y. Niimi، نويسنده , , T. Matsui، نويسنده , , H. Kambara، نويسنده , , K. Tagami، نويسنده , , M. Tsukada، نويسنده , , Hiroshi Fukuyama، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2005
Pages :
6
From page :
43
To page :
48
Abstract :
We studied experimentally and theoretically the electronic local density of states (LDOS) near single-step edges at the surface of exfoliated graphite. In scanning tunneling microscopy measurements, we observed the ð ffiffiffi 3 p ffiffiffi 3 p ÞR30 and honeycomb superstructures extending over 3–4 nm both from the zigzag and armchair edges. Calculations based on a densityfunctional- derived non-orthogonal tight-binding model show that these superstructures can coexist if the two types of edges admix each other in real graphite step edges. Scanning tunneling spectroscopy measurements near the zigzag edge reveal a clear peak in the LDOS at an energy below the Fermi energy by 20 meV. No such a peak was observed near the armchair edge. We concluded that this peak corresponds to the ‘‘edge state’’ theoretically predicted for graphene ribbons, since a similar prominent LDOS peak due to the edge state is obtained by the first principles calculations.
Keywords :
Edge state , Scanning tunneling microscopy , Scanning tunneling spectroscopy , Graphite
Journal title :
Applied Surface Science
Journal title :
Applied Surface Science
Serial Year :
2005
Link To Document :
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