Just when we thought we knew pretty much everything there was to know about carbon, researchers have discovered a brand new phase of solid carbon, called Q-carbon. And they've shown they can use it to create cheap diamonds at room temperature and regular air pressure.
Phases are distinct forms of the same material, and currently there are two known solid phases of carbon: graphite and diamond. But this research reveals a whole new, super rare, phase.
"We've now created a third solid phase of carbon," said lead researcher Jay Narayan from North Carolina State University. "The only place it may be found in the natural world would be possibly in the core of some planets."
In addition to being a novel phase of matter, Q-carbon also has some pretty weird characteristics that the scientists are getting excited about – for example, it's harder than diamond and glows when exposed to even low levels of energy.
It's also ferromagnetic, which neither diamond or graphite are. "We didn't even think that was possible," adds Narayan. "Q-carbon's strength and low work-function – its willingness to release electrons – make it very promising for developing new electronic display technologies."
But for now what's most interesting about Q-carbon is that it can greatly reduce the cost and effort required to make diamond structures, which are used throughout the medical and technology industries. Right now, it usually takes incredible amounts of heat and pressure to produce synthetic diamonds, but the new technique works at room temperature and at ambient pressure.
So how does it work? It all comes down to how Q-carbon is made – the scientists start with a substrate like glass or a plastic polymer, and then coat it with amorphous carbon (a type of carbon that doesn't have a well-defined crystalline structure).
When that carbon is hit with a short laser pulse, the temperature skyrockets to around 3,727 degrees Celsius, before rapidly cooling down and forming a thin film of Q-carbon. But by mixing up the substrate and the duration of the laser pulse, the researchers can change how quickly the material cools down, which means they can create diamond structures with then Q-carbon.
"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.
Nanoneedles and microneedles are tiny needles that can be used in high-precision medical techniques. Nanodots are tiny structures that create super-small magnetic or electrical fields, and can be used to store huge amounts of information and energy, as well as create light emitting devices.
"These diamond objects have a single-crystalline structure, making them stronger than polycrystalline materials," added Narayan. "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."
The ability to quickly, cheaply, and easily make diamonds will be huge for a whole range of industries – not only because of the financial savings, but also because this new technique requires such little equipment.
But the big question is, if Q-carbon is harder than diamond, why don't we just replace diamonds with the new phase? The short answer is because the phase of material is simply too new to be useful just yet.
"We can make Q-carbon films, and we're learning its properties, but we are still in the early stages of understanding how to manipulate it," said Narayan. "We know a lot about diamond, so we can make diamond nanodots. We don't yet know how to make Q-carbon nanodots or microneedles. That's something we're working on."
The discovery will be published across two papers in the Journal of Applied Physics and APL Materials. North Carolina State University now has a patent pending on Q-carbon and the diamond creation technique. We can't wait to find out more.