The structure of fullerene is similar to a football. It served as the starting material for the new substance. Source: Sponk (talk) / Wikipedia
Read aloud So far, carbon in the form of diamonds has been considered the hardest solid in the world? but now US researchers have created an even harder carbon that is even capable of penetrating diamonds. The material is a mixture of ordered and disordered carbon structures that has never been seen before. The element carbon (C) is one of the building blocks of nature and life. It occurs everywhere: in the earth, in the air or in our cells - nothing works without carbon. It is available in many different combinations with other elements, but also in pure modifications, for example as very soft graphite, nanotubes or extremely hard diamond. In these different forms, the carbon atoms are structured differently, either very ordered and with a clearly recognizable structure (crystalline) or disordered, in irregular patterns (amorphous). So far, no mixture of both structures was known, but the scientists around Lin Wang of the Carnegie Institution of Washington have now succeeded in producing such a mixed structure.

The starting material in the experiments was a so-called fullerene: carbon, in which 60 carbon atoms in pentagons? and? hexagons? strung together so that they give a hollow, spherical structure, similar to a football. The fullerene mixed the researchers with m-xylene, the meta-form of the aromatic hydrocarbon xylene. m-xylene is a colorless liquid that often acts as a solvent. This fabric sat down in the spaces between the "fullerene balls". Scientists are now applying pressure to see how the mixture behaves.

At low pressure, the ball structures did not change, but at elevated pressure, the overall picture changed significantly: At approximately 35 gigapascals, the fullerene balls collapsed and formed partially amorphous structures. This end product now revealed a spectacular feature: it's harder than diamond. The final proof was provided by the scientists that they could impress diamonds with the new carbon material.

"We've created a new kind of carbon material that's comparable to diamond, because it can not be compressed as well, " Wang explains. ? Once the material has been produced under extreme pressure, it can also exist under normal conditions, meaning that it can be used for a variety of practical applications.? display

Lin Wang (Carnegie Institution of Washington) et al .: Science; doi: 10.1126 / science.1220522 © - Gesa Seidel


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