The configuration of carbon's electrons allows for numerous self-bonding combinations that give rise to a range of materials with varying properties. For example, transparent, super-hard diamonds and opaque graphite, which is used for both pencils and industrial lubricant, are comprised solely of carbon.
Researchers have developed a form of ultra-strong, lightweight carbon that is also elastic and electrically conductive. A material with such a combination of properties could serve a wide variety of applications, from aerospace engineering to military armor.
In this work, scientists pressurized and heated a structurally disordered form of carbon called glassy carbon. The glassy carbon starting material was brought to about 250,000 times normal atmospheric pressure, and heated to approximately 1800 °F to create the new strong and elastic carbon.
Scientists had previously tried subjecting glassy carbon to high pressures at both room temperature (referred to as cold compression) and extremely high temperatures. But the so-called cold-synthesized material could not maintain its structure when brought back to ambient pressure, and under the extremely hot conditions, nanocrystalline diamonds were formed.
The newly created carbon is comprised of both graphite-like and diamond-like bonding motifs, which gives rise to the unique combination of properties. Under the high-pressure synthesis conditions, disordered layers within the glassy carbon buckle, merge, and connect in various ways. This process creates an overall structure that lacks a long-range spatial order, but has a short-range spatial organization on the nanometer scale. The synthesis method could be honed to create other forms of carbon and entirely different classes of materials.