How is graph extracted from graphite

Nobel Prize in Physics for the discoverer of the graph

A thin layer of ordinary carbon, only one atomic layer thick, has now earned Andre Geim and Konstantin Novoselov the 2010 Nobel Prize in Physics. The two researchers were the first to discover and research the extraordinary properties of graphene, a material that is indispensable today as a material of the future and an important research object in quantum physics.

In principle, graphene is nothing more than carbon atoms, each of which forms hexagonal structures that are arranged in a plane like the pattern of a chain link fence. But although this form of carbon is found in every pencil as graphite, its unusual properties were completely unknown until 2004. This was first discovered by Andre Geim and Konstantin Novoselov, who began their work together in the Netherlands and then moved to the University of Manchester in England in Great Britain.

The discovery: with adhesive tape and silicon plate

With the simplest means they succeeded in extracting the graph from the graphite. With the help of normal adhesive tape, the researchers gradually peeled off ever thinner layers of graphite until they finally received tiny scales of carbon from just a few to just one atomic layer. How thick the flakes were could be deduced indirectly from the play of colors that the particles produced under the microscope.

But how were the scientists supposed to stabilize these flakes so that they could examine them more closely? Here, too, the two found an ingeniously simple solution: They tied the scales to a base made of silicon oxide, the standard carrier material for semiconductors in the computer industry. As it turned out, this preparation was the prerequisite for making the exact structure of graphene visible for the first time under the electron microscope and later also under stronger microscopes.

The properties: extraordinary

The recordings showed for the first time that a genuinely two-dimensional material like graphene can actually exist and is not only stable at room temperature, but also crystalline. The work of Geim and Novoselov opened a whole new field of research on such two-dimensional materials and revealed how extraordinary the properties of these structures are.

Graphene is just as good a conductor as copper, but the best known heat conductor. Almost completely transparent, it is still so dense that not even helium, the gas with the smallest atoms, can penetrate. Today, graphs can be used to study the diverse phenomena of quantum physics in more detail.

The applications: of transparent electronic parts ...

Numerous applications are also based on the properties of this form of carbon. It could be used in the future as a basis for transparent touchscreens, luminous surfaces or maybe even solar cells. In the computer industry, graphene is a promising material for transistors and semiconductors. A graph transistor developed a few years ago turned out to be just as fast as its conventional silicon counterpart, but it is several orders of magnitude smaller. However, graph-based computers are still a long way from being realized.

... to lighter and more stable building materials

Mixed with plastic, it gives it conductivity and greater resistance to heat and mechanical loads. Adding just a fraction of a thousandth of graphene, for example, can increase the heat resistance of plastic by 30 ° C. Research is already being carried out around the world into building materials that are particularly stable but, thanks to graphene, are particularly light and elastic. In the future, satellites, airplanes or cars could also be built from new composite materials based on graphene.

Geim and Novoselov have now received the 2010 Nobel Prize in Physics for their “groundbreaking experiments on the two-dimensional material graphene”.

(Nobel Foundation, October 5, 2010 - NPO)

October 5, 2010