Welcome!

Benvenuti in queste pagine dedicate a scienza, storia ed arte. Amelia Carolina Sparavigna, Torino

Showing posts with label Graphene. Show all posts
Showing posts with label Graphene. Show all posts

Monday, June 27, 2011

A "Mobius" graphene

"In 1858, August Mobius dreamt up a shape with a single surface and only one edge. The Mobius strip has fascinated children and scientists alike since then.
How small can these shapes be? In December 2003, German chemists made a molecular Mobius strip out of a benzene-like ring modified with a belt-like carbon structure. Since then, various groups have produced increasingly bizarre Mobius-type molecules, including one that can switch back and forth from a Mobius to an ordinary strip when zapped with light.
Of course, the obvious choice of material with which to make Mobius molecules is graphene. But this particular trick has eluded chemists, an omission that clearly irks. Now Douglas Galvao from the Universidade Estadual de Campinas in Sao Paolo, Brazil, and buddies have decided to grip the bull by the horns and calculated the properties that Mobius carbon might have."New form of "Mobius" carbon predicted - Technology Review

Thursday, March 31, 2011

Physicists put a new twist on graphene

"Physicists in the US and UK have worked out why different samples of multilayer graphene can have very different electronic properties. The answer, according to the team, lies in the relative rotation between layers and the discovery could lead to a new way of controlling the electronic properties of the material."
Physicists put a new twist on graphene - physicsworld.com

Wednesday, December 29, 2010

Graphene Transistors

Technological Review reports that IBM has created graphene transistors, quite faster that silicon ones. The prototype devices are made from atom-thick sheets of carbon and operate at 100 gigahertz, meaning that they switching on and off 100 billion times each second. As a consequence they are about 10 times as fast as the speediest transistors.