Researchers analyzing the assembly of graphene (sheets of carbon only one
atom thick) on a surface of iridium have found that the sheets grow by first
forming tiny carbon domes. The discovery offers new insight into the growth
of graphene layers and points the way to possible methods for assembling components
of graphene-based computer circuits.
 | | Carbon atoms form dome structures on iridium substrates, en route to forming larger scale graphene sheets. Credit: Image courtesy of Alan Stonebraker. |
Paolo Lacovig, Monica Pozzo, Dario Alfè, Paolo Vilmercati, Alessandro
Baraldi, and Silvano Lizzit at institutions in Italy, the UK and USA report
their discovery in a paper appearing October 12 in the journal Physical
Review Letters. The researchers' spectroscopic study suggests that graphene
grows in the form of tiny islands built of concentric rings of carbon atoms.
The islands are strongly bonded to the iridium surface at their perimeters,
but are not bonded to the iridium at their centers, which causes them to bulge
upward in the middle to form minuscule geodesic domes. By adjusting the conditions
as the carbon is deposited on the iridium, the researchers could vary the size
of the carbon domes from a few nanometers to hundreds of nanometers across.
Investigating the formation of graphene nanodomes helps physicists to understand
and control the production of graphene sheets. In combination with methods for
adjusting the conductivity of graphene and related materials, physicists hope
to replace electronics made of silicon and metal with tiny, efficient carbon-based
chips.
Jorge Sofo and Renee Diehl (Penn State University) highlight the graphene nanodome
research in a Viewpoint in the October 12 issue of Physics (physics.aps.org).
Also in Physics: Clearing Up Electron Microscopy Aberrations, and Yoctosecond
Flashes from Quark Gluon Plasmas
A Viewpoint by Robert Klie (University of Illinois at Chicago) describes an
approach for reducing aberrations in electron microscopy, setting a new standard
for low-energy imaging. And Abishek Agarwal (American Physical Society) offers
a Synopsis of a model that suggests that quark-gluon plasmas produced in particle
colliders could emit the briefest light bursts yet, potentially offering illumination
for ultra-fast images of high speed events in atomic and molecular experiments
About APS Physics: APS Physics (physics.aps.org) publishes expert written commentaries
and highlights of papers appearing in the journals of the American Physical
Society.
Posted October 11th, 2009
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