The Next Graphene? Shiny and Magnetic, a New Form of Pure Carbon Dazzles

sciencehabit quotes Science magazine: A “happy accident” has yielded a new, stable form of pure carbon made from cheap feedstocks, researchers say. Like diamond and graphene, two other guises of carbon, the material seems to have extraordinary physical properties. It is harder than stainless steel, about as conductive, and as reflective as a polished aluminum mirror. Perhaps most surprising, the substance appears to be ferromagnetic, behaving like a permanent magnet at temperatures up to 125 degrees C — a first for carbon. The discovery, announced by physicist Joel Therrien of the University of Massachusetts in Lowell on 4 November here at the International Symposium on Clusters and Nanomaterials, could lead to lightweight coatings, medical products, and novel electronic devices…. The magnetism adds to a suite of properties never before seen together in a form of pure carbon. They include tremendous hardness that presumably results from the bonds joining adjacent layers: “We’ve tried scratching it with steel wool, and it comes off clean,” Therrien says. “The only thing we can say verifiably scratches it is a diamond scribe.” Though the group has yet to measure the tensile strength of the material, the fact that vanishingly thin flakes hold together at millimeter size suggest it may be as strong as some metals, he says. Then there is the mirrorlike appearance, seen in photos Therrien showed at the meeting. The team’s measurements indicate that the film, even when just 50 nanometers thick, reflects more than 90% of incoming light at wavelengths ranging from the far-ultraviolet to the midinfrared. That attribute could make it a useful reflective coating, more durable than the standard aluminum, for mirrors in cameras and telescopes. Its electrical conductivity turned out to be just shy of that of stainless steel. But it can also display other electronic properties. Annealing the material by slowly heating it to 1000 degrees C dims its shine and turns it into a semiconductor with a band gap — the energy required to liberate an electron — similar to that of amorphous silicon, which can turn light into electricity. That makes it a candidate material for photovoltaic cells, Therrien suggests.