Natural diamonds take billions of years to form, being associated with immense exclusivity and being available at unaffordable prices. Considering the artificial process – still time-consuming –, scientists have now managed to create diamonds in just 150 minutes.
As is known, natural diamonds take billions of years to form under extreme pressures and temperatures deep underground. In turn, synthetic forms can be produced much more quickly. However, they usually still require intense crushing for several weeks.
A new method based on a mixture of liquid metals can create an artificial diamond in a matter of minutes, without the need for brutal crushing. Even though very high temperatures (1025 °C) were still required, a diamond film was formed in 150 minutes, and at one standard atmosphere unit (atm), that is, tens of thousands of times less than the pressure normally required.
The team, led by researchers from the South Korea Institute of Basic Sciences, believes the process could make a significant difference in the production of synthetic diamonds.
Form diamonds without taking billions of years
Dissolving carbon in liquid metal to make diamonds is not entirely new. After all, General Electric developed a process many years ago, using cast iron sulfide, for example.
However, these processes continued to require pressures of 5-6 gigapascals and a diamond “seed” for the carbon to cling to.
We have discovered a method to produce diamonds at a pressure of 1 atm and a moderate temperature using a liquid metal alloy.
Read the article published in Nature.
The pressure reduction was achieved using a careful mixture of liquid metals: gallium, iron, nickel and silicon. A custom-made vacuum system was built into a graphite casing, with the aim of very quickly heating and then cooling the metal while it was exposed to a combination of methane and hydrogen.
These conditions cause the carbon atoms in methane to spread throughout the molten metal, acting as seeds for the diamonds. Relatively shortly thereafter, small fragments of diamond crystals were expelled from the liquid metal just below the surface, while two and a half hours of exposure produced a continuous film of diamond.
Although the concentration of carbon that forms the crystals has decreased to a depth of just a few hundred nanometers, researchers hope the process can be improved with some tweaks.
We suggest that simple modifications could allow diamond growth over a very large area by utilizing a larger surface or interface, configuring the heating elements to obtain a much larger potential growth region, and distributing the carbon in the diamond growth region in some new ways. .
The researchers wrote.
These modifications will take time and research into this process is still in its early stages. However, the authors of the new study think it has a lot of potential – and that other liquid metals could be incorporated to achieve similar or better results.
The process currently used to create most synthetic diamonds – used for a wide variety of industrial processes, electronics and even quantum computers – takes several days and requires much more pressure. If this new technique meets expectations, diamond production will become much faster and much easier.
The general approach of using liquid metals can accelerate and advance the growth of diamonds on a variety of surfaces, and perhaps facilitate the growth of diamonds on small diamond particles (seeds).
