The known phases of carbon pertains to the familiar graphite and diamond, as they are distinct forms of the same material. But this time around, researchers at the North Carolina State University have made a momentous discovery by finding a brand new phase of solid carbon which is termed as Q-carbon. And the really interesting part is – they have also showcased how this new (and extremely rare) phase of carbon can be utilized to create cheap diamonds at room temperature with only ambient atmospheric pressure.
So how exactly is the Q-carbon different from its phase ‘cousins’? Well for starters, this phase was found to be both harder than diamond and ferromagnetic – a quality not shared by the other solid carbons. And if that was surprising, hear this out – the Q-carbon was also found to glow when exposed to energies of even lower magnitude. Such characteristics do allude to great potential for electronic display technologies of the future.
But for now, the real advantage of the Q-carbon relates to its usage in manufacturing of low-cost, single-crystal diamond structures that are widely used in both engineering and medical fields (including drug delivery and therapeutics). Simply put, the scope can totally avoid the need for conventional synthetic diamonds that are rather unwieldy to produce given their propensity for high heat and pressure requirements.
On the other hand, the production method for the Q-carbon is pretty straightforward. The scientists started out by opting for a substrate, which can usually be sapphire or glass (or even a plastic polymer). This chosen substrate was then coated with amorphous carbon, known for its irregular structure, unlike diamond or graphite. Subsequently, the layered carbon was targeted with a single laser pulse, and the beam on hitting the substance for 200 nanoseconds, led to a temperature of 3,727 degrees Celsius. The carbon was then cooled off, and the resulting film was found to be that of Q-carbon – created under one atmosphere, the optimized pressure in air.
The researchers found that they could control the thickness of the Q-carbon layer (ranging from 20 nanometers to 500 nanometers) by regulating the duration of the laser and using variant substrates. And on stretching the ambit a bit, they could also create the aforementioned single-crystal diamond structures by simply adjusting the rate of cooling of the carbon layer. As Jay Narayan, the lead author of the study, reiterated –
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. 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.
In other words, the technological scope doesn’t only eschew the cost side of affairs, but also embraces relatively simple equipment for creating the new carbon phase and single-crystal diamond structures. To that end, the question naturally arises – if Q-carbon is harder than diamond, then why not replace diamond nanodots with Q-carbon? The answer to that is actually very simple; Q-carbon is still a very new material, as opposed to the tried-and-tested applications of diamond. Simply put, scientists are still working out on the details of this incredible carbon phase which can potentially reveal more qualities of the material in the near future. Meanwhile, North Carolina State University has taken the pertinent step in applying for a Q-carbon patent.
The study will be published in both Journal of Applied Physics and APL Materials.
Source: ScienceDaily