Natural diamonds take billions of years to form under extreme pressures and temperatures deep within the Earth. Synthetic forms can be produced much faster, but usually require some intensive crushing for up to several weeks.
A new method based on a mixture of liquid minerals can extract synthetic diamonds within minutes, without requiring much pressure.
While high temperatures were still required, in the region of 1025°C or 1877°F, a continuous diamond film was formed in 150 minutes, and at 1 atm (or standard atmospheric unit). This is equivalent to pressure We feel at sea leveland tens of thousands of times lower than the pressure normally required.
The team behind this innovative approach, led by researchers from the Institute of Basic Sciences in South Korea, is confident that the process can be scaled up to make a big difference to the production of synthetic diamonds.
Melting carbon into liquid metal to make diamonds isn't exactly new. General Electric developed a process half a century ago using molten iron sulfide, for example.
But these processes still require stress 5-6 GPa The diamond “seed” to which the carbon is attached.
“We have discovered a way to grow diamonds at one atmosphere of pressure and moderate temperature using a liquid metal alloy.” He writes The researchers in their published paper.
Pressure drop It was achieved using a carefully mixed mixture of liquid metals: gallium, iron, nickel and silicon. A specially made vacuum system is built inside the graphite shell to very quickly heat the metal and then cool it while it is exposed to a mixture of methane and hydrogen.
These conditions cause carbon atoms from the methane to disperse into the molten metal, serving as seeds for the diamonds. After just 15 minutes, tiny fragments of diamond crystals emerged from the liquid metal just below the surface, while a two-and-a-half-hour exposure produced a continuous diamond layer.
Although the concentration of carbon that forms the crystals was reduced to a depth of only a few hundred nanometers, the researchers expect that the process can be improved with just a few tweaks.
“We propose that direct modifications could enable diamond growth over a very large area using a larger surface or interface, by configuring the heating elements to achieve a much larger potential growth area and distributing carbon over the diamond growth area in some new ways.” He writes Researchers.
These modifications will take some time, and research into this process is still in its very early stages, but the authors of the new study believe it has a lot of potential — and that other liquid metals could be combined to get similar materials or better results.
The process currently used to create most Synthetic diamonds – It is used for a wide range of industrial processes, electronics and even quantum computers – It takes several days and requires more pressure. If this new technology achieves its potential, diamond making will become much faster and much easier.
“The general approach of using liquid metals can accelerate and enhance diamond growth on a variety of surfaces, and possibly facilitate diamond growth on small diamond particles (seeds).” He writes Researchers.
The research was published in nature.
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