terça-feira, 5 de outubro de 2010

Nobel de Física de 2010

Konstantin Novoselov, left, and Andre Geim.

Dois Pesquisadores jovens ganham Nobel de Fisica. Jovens ganham prêmio pela descoberta de uma fibra de carbono denominada Grafene.

Interessante, existe um prêmio nobel pelo pior trabalho, denominado Ig Nobel (pesquisa improvável). Um deles, Andre Geim ganhou esse prêmio em 2000 pelo experimento de fazer flutuar uma rã em campo magnético

Physics Nobel Honors Work on Ultra-fine

A pair of Russian-born physicists working at the University of Manchester in England have won the Nobel Prize in Physics for investigating the remarkable properties of ultra-thin carbon flakes known as graphene, the Royal Swedish Academy of Sciences said Tuesday.

Thin Carbon Is In: Graphene Steals Nanotubes’ Allure (April 10, 2007)
They are Andre Geim, 51, and Konstantin Novoselov, 36. They will split the prize of about $1.4 million.

Graphene is a form of carbon in which the atoms are arranged in a flat hexagon lattice like microscopic chicken wire, a single atom thick. It is not only the thinnest material in the world, but also one of the strongest. If scaled up to the thickness of plastic refrigerator wrap, a sheet of graphene stretched over a coffee cup could support the weight of a truck bearing down on a pencil point, according to tests conducted by two Columbia University researchers, Jeffrey Kysar and James Hone.

Among its other properties, graphene is able to conduct electricity as well as copper does and to conduct heat better than any other known material, and it is completely transparent. Physicists say that it could eventually rival silicon as a basis for computer chips, serve as a sensitive pollution-monitoring material, improve flat screen televisions, and enable the creation of new materials and novel tests of quantum weirdness, among other things.

In a statement, the Royal Academy said, “Carbon, the basis of all known life on earth, has surprised us once again.”

Graphene is closely related to two other forms of carbon that have generated intense interest in recent years: buckyballs, which are soccer-ball arrangements of carbon atoms, and nanotubes, which are rolled-up sheets of carbon atoms. It was long thought, however, that an essentially two-dimensional sheet of carbon atoms would be unstable and would warp or fold up. Dr. Geim and Dr. Novoselov first succeeded in creating flakes of graphene by peeling them off piles of graphite — the material that is in your pencil lead — using Scotch tape.

Dr. Geim, who was born in Sochi, Russia, and is now a Dutch citizen, studied at the Moscow Physical-Technical Institute and was awarded a Ph.D. at Institute of Solid State Physics in Chernogolovka in 1987. He led a wandering research life — “Sometimes I joke that I am not interested in doing re-search, only search,” he told ScienceWatch.com in 2008 — before he became a professor at the University of Nijmegen in Holland.

It was at Nijmegen that he connected with Dr. Novoselov, who was born in Nizhny Tagil, and became Dr. Geim’s graduate student in the Netherlands. When Dr. Geim subsequently moved to the University of Manchester he brought Dr. Novoselov with him; Dr. Novoselov is now a British and Russian citizen.

The graphene creation originated in what Dr. Geim and Dr. Novoselov call “Friday evening” experiments, crazy things that might or might not work out.

In one of them, Dr. Geim managed to levitate a frog in a magnetic field, for which he won an IgNobel — a parody award for “improbable research” — in 2000.

The work on graphene arose from the pair’s desire to investigate the electrical properties of graphite. To do that, however, they needed very thin pieces, which they first tried to produce by filing down graphite crystals, with no luck. Then a technician showed them how graphite was cleaned before being observed in a scanning tunneling microscope by peeling layers off with Scotch tape.

“We knew about the method before, but everything is good in its own time, so one glance at it and we knew — that must be it,” Dr. Novoselov told ScienceWatch.com in 2009.

The technique is still used. “It’s called the “Scotch tape technique,” Dr. Geim told ScienceWatch. “I fought against this name, but lost. It doesn’t sound very high-tech, does it?”

Their first paper on graphene was published in Science in 2004, after being rejected by Nature. A second paper appeared in 2005. Since then, the Swedish Academy said, “research in this area has literally exploded,” producing a growing number of papers about the material, its properties and its promise.

Dr. Geim said there was also cornucopia of new physics to be explored.

Because of graphene’s structure, he explained, electrons moving through it do not act like the billiard balls of classic physics, bumping from atom to atom, but rather like waves moving at the speed of light.

“That’s a new kind of thing to study. It’s like the Large Hadron Collider, but on your desktop,” Dr. Geim said in his ScienceWatch.com interview.

Nenhum comentário:

Postar um comentário