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Topic: Graphene

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	Controlling Graphene's Electronic Structure
		Graphene's intrinsically low scattering rate from defects implies the possibility of a new kind of electronics based on the manipulation of electrons as waves rather than particles.
		Graphene's unique electronic structure is characterized by conical valence and conduction bands that meet at a single point in momentum space (the Dirac crossing energy).
		When the researchers first synthesized their bilayer graphene films onto the silicon carbide substrate, the graphene became a weak n-type semiconductor, having a slight excess of negatively charged electrons; the interface layer acquired an excess of conduction electrons from the substrate, creating a small bandgap.
	www-als.lbl.gov /als/science/sci_archive/140graphene.html (1013 words)

	American Elements: Graphene Supplier & Tech Info
		Nano Carbon Graphene is also available in passivated and Ultra high purity and high purity and coated and dispersed forms.
		Research into applications for carbon graphene nano sheets has focused on uses as active materials in field emitter arrays for flat panel screen displays, in biological sensors and medical imaging devices, in solar energy cells, and in high-surface area electrodes for use in bio-science.
		Magnetic confinement of massless Dirac fermions in graphene.
	www.americanelements.com /cgnf.html (178 words)

	Graphene provides foundation for new devices that handle electrons as waves
		Unlike carbon nanotubes, however, graphene circuitry can be produced using established microelectronics techniques, allowing researchers to envision a "road map" for future high-volume production.
		In their paper, the researchers report seeing evidence of quantum confinement effects in their graphene circuitry, meaning electrons can move through it as waves.
		Among the challenges ahead is improving the techniques for patterning the graphene, since electron transport is affected by the smoothness of edges in the circuitry.
	www.physorg.com /news64239590.html (1105 words)

	Researchers develop foundation for circuitry and devices based on graphite
		Using thin layers of graphite known as graphene, researchers at the Georgia Institute of Technology in the United States, in collaboration with the Centre National de la Recherche Scientifique (CNRS) in France, have produced proof-of-principle transistors, loop devices and circuitry.
		Continuous graphene circuitry can be produced using standard microelectronic processing techniques, potentially allowing creation of a “road map” for high-volume graphene electronics manufacturing, he said.
		Graphene systems could also be used as the foundation for molecular electronics, helping resolve resistance issues that now affect such systems.
	gtresearchnews.gatech.edu /newsrelease/graphene.htm (951 words)

	The Hindu : Sci Tech / Speaking Of Science : Graphene: the magic carpet made of carbon
		A typical graphene has the chemical formula C{-6} 2H{-2}O. In effect, it is a flake of graphite with hydrogen atoms used to terminate the dangling bonds.
		Graphene is thus a sheet of interlocked hexagons of carbon.
		Graphene is the latest addition to the family of the fullerenes and nanotubes.
	www.hindu.com /seta/2006/04/06/stories/2006040600971700.htm (984 words)

	EETimes.com - Graphene transistor to rival silicon, say researchers
		The substance, dubbed graphene, is described as a two-dimensional material that exhibits exceptionally high crystal and electronic quality, and the researchers claim has numerous potential applications in condensed matter physics and electronics.
		The thinness of graphene membranes is such that the electrons would have much less irrelevant material to pass through and so be able to give a clearer picture of the structure of molecules.
		They suggest graphene membranes could eventually replace silicon because they have the potential to be a far more effective transistor.
	www.eetimes.com /rss/showArticle.jhtml?articleID=197700700 (765 words)

	Graphene Provides Foundation For New Electronics
		Graphics: Photographs of researchers with laboratory equipment, scanning electron microscope images of graphene circuitry, prototype graphene device.
		Iridium Satellite, KDDI Network and Solutions and Pioneer Navicom jointly announce the completion of successful air trials and initial deployment of an automatic helicopter tracking system by the Japanese Fire and Disaster Management Agency.
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	www.spacemart.com /reports/Graphene_Provides_Foundation_For_New_Electronics.html (1215 words)

	KITP - Electronic Properties of Graphene (Minipgm)
		Graphene is a condensed matter realization of the Dirac equation since the electronic dispersion close to the Brillouin zone edges are conical with a Fermi-Dirac velocity of order of one hundredth of the velocity of light.
		In fact, graphene shares many properties with quasi-two-dimensional d-wave superconductors (such as superconducting cuprates) which can also be described in terms of Dirac-like excitations.
		Because of its high electronic mobility, structural flexibility, and capability of being tuned from p-type to n-type doping by the application of a gate voltage, graphene is considered a potential breakthrough in terms of carbon-based nano-electronics.
	www.itp.ucsb.edu /activities/auto2/?id=728 (320 words)

	Graphene sheet can be more economical than carbon nanotube for plastic composites
		Graphene sheet is a thin film of carbon that is just one atom thick embedded in a polymer matrix.
		Graphene, a novel type of material with good electrical properties - can be made by rubbing tiny pieces of its precursor, graphite, against a hard surface to detach flakes of the carbon material.
		Graphene appears to have many electronic properties similar to carbon.
	www.plastemart.com /upload/Literature/Graphene_sheet.asp (510 words)

	Scientific American: Move Over Nanotube, Here Comes Graphene
		Although graphene, too, faces many obstacles on the road to applications, its combination of exotic physics and high-tech potential is attracting scores of researchers.
		Graphene, like the carbon nanotube, meets the first requirement: it is a snappy conductor of electricity—better than many semiconductors.
		It also leaves graphene with ragged edges, because the electrons that made chemical bonds with the excised carbon atoms remain like loose threads, interfering with passing electrons and dragging down the ribbon's current.
	www.sciam.com /print_version.cfm?articleID=DCCF6BAB-E7F2-99DF-3598F37C1D4966C9 (1751 words)

	BBC NEWS \| Science/Nature \| Radical fabric is one atom thick
		Called graphene, it is a two-dimensional, giant, flat molecule which is still only the thickness of an atom.
		Graphene is part of the family of famous fullerene molecules, discovered in the last 20 years, which include buckyballs and nanotubes.
		The team is currently experimenting with relatively small sheets of the graphene nanofabric, 10s of microns (millionths of a metre) across, but the sheets are still "large" in molecular terms.
	news.bbc.co.uk /2/hi/science/nature/3944651.stm (601 words)

	Graphene resonator is one atom thick (January 2007) - News - nanotechweb.org
		First made in 2004, graphene sheets are tiny flakes of graphite that can be as little as one atomic layer thick.
		The graphene flakes were dropped across trenches 1 to 5 microns wide, adhering to tops thanks to the van der Waals attraction.
		However, in some cases the graphene failed to span the trench and attached to one side instead to form a diving-board like structure called a "cantilever beam".
	nanotechweb.org /articles/news/6/1/18/1?rss=2.0 (491 words)

	New Graphene Transistor \| Technology News Daily (Site not responding. Last check: 2007-10-22)
		These one-atom-thick materials and particularly graphene - a gauze of carbon atoms resembling a chicken wire - have rapidly become one of the hottest topics in physics.
		But these graphene transistors were very 'leaky' (2), which has limited possible applications and ruled out important ones, such as their use in computer chips and other electronic circuits with a high density of transistors.
		But he believes graphene is probably the only viable approach after the silicon era comes to an end.
	www.technologynewsdaily.com /node/6168 (777 words)

	Research
		Graphene is an atomically two-dimensional electron system made of a single layer of carbon atoms arranged on a honeycomb lattice.
		Interest in graphene has exploded in recent years because of the achievements of experimental research groups at the University of Manchester and Columbia University who have managed to isolate graphene layers and measure their electrical properties.
		At low-energies graphene is described by relativistic quantum mechanics with the role of spin played by the psedospin degree of freedom associated with the two atoms in the honeycomb lattice unit cell.
	www.ph.utexas.edu /~macdgrp/research.html (911 words)

	SupraCarbonic, LLC (Site not responding. Last check: 2007-10-22)
		Graphene is a two-dimensional structure related to buckyballs and nanotubes, and is part of the family of fullerene molecules.
		Films of graphene several nanometers thick are believed to have astounding electronic and chemical properties that wll allow composition of stable materials, and ultimately, theproduction of ultra-fast ballistic transistors.
		Until the recent introduction of SupraCarbonic's graphene, it was presumed that two-dimensional graphene was too unstable to exist in the free state, instead forming curved structures such as fullerenes and nanotubes.
	www.supracarbonic.com (168 words)

	Small Systems Laboratory (Site not responding. Last check: 2007-10-22)
		In fact it was recognized early on the electronic properties of nanotubes stem from the properties of a single graphene layer and its unusual band structure.
		In particular theoretically studies show that graphene ribbons may be either metallic or semiconducting depending on the crystallographic direction of the ribbon axis.
		A major difference between planar graphene ribbons and is the presence of dangling bonds on a graphitic ribbon (which are closed in a nanotube).
	www.physics.gatech.edu /npeg/npeg.html (822 words)

	Graphene Discovery Leads to Top Physics Prize
		Among them is graphene, which has proven to be very useful to science in a number of ways.
		Graphene is a single layer of carbon atoms densely packed in a honeycomb crystal lattice.
		One of many unique properties of graphene is that its electrons mimic particles moving with the speed of light, which presents an easy way for scientists to study relativistic phenomena.
	www.photonics.com /content/news/2006/October/23/84789.aspx (688 words)

	Graphene Transistors Promise Life After Silicon
		These one-atom-thick materials and particularly graphene – a gauze of carbon atoms resembling a chicken wire – have rapidly become one of the hottest topics in physics.
		But these graphene transistors were very 'leaky' (2), which has limited possible applications and ruled out important ones, such as their use in computer chips and other electronic circuits with a high density of transistors.
		But he believes graphene is probably the only viable approach after the silicon era comes to an end.
	www.hpcwire.com /hpc/1292841.html (761 words)

	Graphene (Site not responding. Last check: 2007-10-22)
		Graphene integer quantum Hall effect in the ferromagnet and paramagnetic regimes (J. and M. Fisher, PRB 74, 075422 (2006))
		Many interesting features of graphene stem from the fact that at half-filling the band structure near the Fermi level consists of two linearly dispersing Dirac cones.
		Initial observations of a quantum Hall effect in graphene were consistent with this approximate Landau level degeneracy: the Hall conductivity jumped by 4e^2/h between neighboring plateaus.
	www.physics.ucsb.edu /~aliceaj/Graphene.html (332 words)

	Graphene - Nanofabric One Atom Thick: Science Fiction in the News
		The graphene nanofabric belongs to the family of fullerene molecules (buckyballs and nanotubes); this is the first truly two-dimensional fullerene.
		As for other applications, graphene is basically an "unrolled" nanotube; most of the applications considered for nanotubes would also apply to graphene itself.
		As soon as I read this story, the graphene nanofabric reminded me of the Gauzy, a feather-light tent described as being made of a material just one molecule in thickness, yet strong and flexible.
	www.technovelgy.com /ct/Science-Fiction-News.asp?NewsNum=239 (379 words)

	Lowly graphite stirs new excitement
		Graphene sheets several atoms thick may be able to conduct electricity with almost no resistance, they claimed.
		De Heer also noted that graphene is related to another exotic material that has stirred excitement among physicists in recent years, “carbon nanotubes,” sub-microscopic tubes of carbon atoms linked together like rolled-up chicken wire.
		Graphene by itself is “too soft and flaky” for many applications, wrote Nicholas Kotov of the University of Michigan in Ann Arbor, Mich., in a commentary in the same issue of the journal.
	www.world-science.net /othernews/060724_graphene.htm (951 words)

	Atom-thick graphene transistor could solve problem of silicon chips
		Graphene is a flat sheet of carbon that is extremely stable, strong and flexible, and has high electrical conductivity with little resistance.
		Graphene was discovered in 2004 by the University of Manchester team, which made a cruder version of the transistor at the time.
		Last fall, Geim was awarded the 2007 Mott Medal and Prize by England's Institute of Physics for leading the researchers whose discovery of graphene led to a new category of material known as two-dimensional atomic crystals.
	www.cbc.ca /technology/story/2007/02/28/tech-graphenechip-20070228.html (1340 words)

	Embedded.com - Graphene transistor to rival silicon, say researchers
		The substance, dubbed graphene, is described as a two-dimensional material that exhibits exceptionally high crystal and electronic quality, and the researchers claim has numerous potential applications in condensed matter physics and electronics.
		The thinness of graphene membranes is such that the electrons would have much less irrelevant material to pass through and so be able to give a clearer picture of the structure of molecules.
		They suggest graphene membranes could eventually replace silicon because they have the potential to be a far more effective transistor.
	embedded.com /showArticle.jhtml?articleID=197700758 (738 words)

	Physics graduate student creates graphene resonator
		The graphene is in contact with a gold electrode that can be used to electrostatically actuate the...
		Bunch found that a single sheet of graphene, a form of carbon atoms in a plane just one atom thick, can be isolated and used as an electromechanical resonator.
		The material could be useful for weighing atoms and molecules, which have extremely small masses; as a membrane to separate gases or to measure pressure; or for other experiments that call for a very stiff but exceptionally thin and light sheet of material.
	www.eurekalert.org /pub_releases/2007-02/cuns-pgs021607.php (515 words)

	Technology Review: New Graphene Transistors Show Promise
		The researchers' device, which is the first single-electron transistor to operate at room temperature, offers evidence that graphene is a promising alternative to silicon, which, in the coming decades, is expected to reach its physical limits as a material for making ever-smaller transistors.
		When members of Geim's group first announced their fabrication of graphene, they also demonstrated how it could be used to make a transistor.
		Although the two are similar, graphene (consisting of just one layer of graphite) research is very new.
	technologyreview.com /Infotech/18264 (760 words)

	Georgia Institute of Technology :: News Room :: Graphite Provides New Foundation for Circuitry
		Using thin layers of graphite known as graphene, researchers at the Georgia Institute of Technology in the United States, in collaboration with the Centre National de la Recherche Scientifique (CNRS) in France, have produced proof-of-principle transistors, loop devices and circuitry.
		Continuous graphene circuitry can be produced using standard microelectronic processing techniques, potentially allowing creation of a “road map” for high-volume graphene electronics manufacturing, he said.
		Graphene systems could also be used as the foundation for molecular electronics, helping resolve resistance issues that now affect such systems.
	www.gatech.edu /news-room/release.php?id=890 (1068 words)

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