| Author(s): |
Eric J. Cockayne; Gregory M. Rutter; N Guisinger; Jason Crain; Joseph A. Stroscio; Phillip First; |
| Title: |
Rotational Grain Boundaries in Graphene |
| Published: |
May 12, 2011 |
| Abstract: |
Defects in graphene are of interest for their effect on electronic transport in this two-dimensional material. Point defects of typically two-fold and three-fold symmetry have long been observed in scanning tunneling microscopy (STM) studies of graphite. In epitaxial graphene grown at high temperatures on mechanically-polished SiC(0001), we observe a 6-fold "flower" defect by STM, with enhanced differential tunnel conductance over the 2 nm extent of the defect. Density functional theory calculations suggest that the defect is a rotational grain boundary made up of five- and seven-membered carbon rings. The observed defect is the smallest member of a family of rotational grain boundaries characterized by two integers, (m,n), which correspond to rotations of the hexagonal lattice within the core of the defect by (n/m)x(60 degrees) with respect to the outside lattice. Simulated STM topographs of the (2,1) rotational defect are in agreement with experiment. |
| Citation: |
Physical Review B |
| Volume: |
83 |
| Pages: |
7 pp. |
| Keywords: |
graphene; defects; grain boundaries; STM imagery |
| Research Areas: |
Nanoelectronics and Nanoscale Electronics |
| PDF version: |
 Click here to retrieve PDF version of paper (5MB) |
