New form of solid carbon exhibits diverse range of properties

The new form, or phase, has been named Q-carbon and it has a range of surprising properties, such as being ferromagnetic, harder than diamond, and glowing in the dark when exposed to low energy. Other forms of solid carbon are non-magnetic.  

“We’ve now created a third solid phase of carbon,” said Jay Narayan, a professor of materials science and engineering at NC State and lead author of three papers describing the work. “The only place it may be found in the natural world would be possibly in the core of some planets.”

Q-carbon is produced by starting with a substrate such as sapphire, glass or a plastic polymer. This is then coated with elemental carbon that does not have a well-defined crystalline structure like graphite or diamond. The carbon is hit with a single laser pulse lasting around 200 nanoseconds, raising its temperature to about 4,000 Kelvin. After cooling rapidly, a thin film of Q-carbon is left. Films can be made to thicknesses between 20 and 500 nanometres.