Researchers from North Carolina State University have discovered a new phase of solid carbon called Q-carbon. Phases refer to distinct forms of the same material and currently, researchers are aware of two phases - graphite and diamond. The recent discovery is outlined in a paper that also explores a technique for using the new phase of carbon to create diamond-like structures at room temperature.
"We've now created a third solid phase of carbon," Jay Narayan, lead author of the paper, said in a press release. "The only place it may be found in the natural world would be possibly in the core of some planets."
Q-carbon is ferromagnetic, meaning that below a certain temperature it can possess magnetization even in the absence of an external magnetic field, something that Narayan and his team found shocking.
"We didn't even think that was possible," he said.
Using a single substrate, the researchers used laser beams to raise and subsequently rapidly cool the temperature of amorphous carbon, which is different from graphite and diamond due to the fact that it has no fixed structure.
This process took place at just one atmosphere, which is the same pressure as the surrounding air. The end result of the process is Q-carbon, which scientists can further manipulate by using various substrates and changing the direction of the laser pulse to control how fast the carbon cools, allowing them to create diamond-like structures.
"We can create diamond nanoneedles or microneedles, nanodots, or large-area diamond films, with applications for drug delivery, industrial processes and for creating high-temperature switches and power electronics," said Narayan. "These diamond objects have a single-crystalline structure, making them stronger than polycrystalline materials. And it is all done at room temperature and at ambient atmosphere - we're basically using a laser like the ones used for laser eye surgery. So, not only does this allow us to develop new applications, but the process itself is relatively inexpensive."
