They are now able to produce astraight edged graphene ribbon and this allows them to discover the quantumeffects produced. Again we are advancingout knowledge. I merely want them tomaster the cart of producing a continuous ribbon that we can wind with manyothers to produce the space hook cable between the Earth’s surface and ageostationary station above it.
We are obviously getting thereand we will soon see manufacturing protocols producing unbelievable products.
As mentioned and discussed manytimes before, this will allow us the build MFEV or magnetic field exclusion vesselsable to travel into space and throughout our solar system at one Gacceleration. (also called UFOs)
Unzipped graphene reveals its secrets
May 13, 2011
Researchers in the US
Graphene is a sheet of carbon just one atom thick and nanoribbons ofthis material are strips of graphene just nanometres across. Physicistsbelieve that, depending on the angle at which they are cut, such ribbons shouldhave a range of different – and technologically useful – electronic,magnetic and optical properties. These properties include band gaps, such asthose found in semiconductors, that do not exist in larger sheets of graphene.
However, until now, scientists have been unable to test thesepredictions because they could not study the atomic-scale structure at theedges of cut nanoribbons – and therefore ensure their samples have the appropriateedges. This is because as-produced nanoribbons are typically disorderedstructures with only short stretches of straight edges.
Unzipping carbon
Michael Crommie's team at the Lawrence Berkeley National Laboratory(LBNL) and the University of California, Berkeley (UCB) has overcome thisproblem by looking at specially made nanoribbons with smooth edges using ascanning tunnelling microscope (STM). These ribbons were obtained fromHongjie Dai's group at Stanford University
The researchers discovered that these ribbons support 1D electronicedge states and that electrons in these states are confined to the nanoribbonedge and have an energy gap. "This kind of behaviour has been predictedfor many years but never experimentally verified," Crommietold physicsworld.com.
The LBNL–UCB team began by spin coating the nanoribbons onto clean goldcrystals. Next, the scientists cooled the nanoribbon-decorated gold crystalsdown to 6 K and imaged them with an STM. "We were able to see theatomic-scale structure of the nanoribbons and use the STM to measure the localdensity of states of the edge states – that is, we measured 'where' theelectrons are," explains Crommie. "In other words, by measuring thecurrent at the STM tip at different locations near the nanoribbon edge, we wereable to determine the spatial distribution of electrons confined near theedge."
"Nanoribbon edge states are real"
Research teams around the world have predicted that the novelelectronic, optical and magnetic properties of such nanoribbons edges could beexploited, in principle, to make new types of devices – such as spin-valves,nanoribbon switches, detectors and photovoltaics from graphene. "Our newexperimental results bolster the pursuit of these applications because we nowknow that the nanoribbon edge states are real," says Crommie.
"The work could also help us better understand the basic physicsof what happens at the edges of graphene samples", he adds. Edges are asimportant and as useful as any other part of graphene, especially as the sizeof nanostructure-based devices is reduced to atomic length scales. "Understandinggraphene edge behaviour, however, has lagged behind other graphene researchbecause of the difficulties of preparing and probing smooth grapheneedges," says Crommie. "Our new results advance our ability tocontrol and characterize graphene-edge nanostructures and so help to push thefield forward and spur new ideas and applications."
Xiaoting Jia of the Massachusetts Institute of Technology, who was notinvolved in the work, can see its merits. "This work is a big step towardsunderstanding and controlling the unique electronic properties in graphenenanoribbon edges, and opens up many opportunities in the electronics,spintronics and optical applications of graphene nanoribbons," he says.
Crommie's team is now interested in modifying graphene edges indifferent ways – for example through electronic doping. "We want toexplore nanoribbon edge behaviour under different conditions, both to testtheories regarding behaviour in the materials and to perhaps discover new, unexpectedphenomena," reveals Crommie. "One of our goals is to fabricatenanoribbon devices that allow us to simultaneously probe atomic-scalenanoribbon structure and device performance, and to correlate theseproperties."
The results were detailed in Nature Physics 10.1038/nphys1991
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