This breakthrough was achieved by a team from the Institute for Basic Science (IBS) and the Ulsan National Institute of Science and Technology (UNIST). Their technique involves synthesizing diamonds using a liquid metal alloy composed of gallium, iron, nickel, and silicon. In a 9-liter (2.4-gallon) tank, this metal mix is exposed to methane and hydrogen gas at a temperature of 1,025 °C (1,877 °F). After 15 minutes, the gases are purged, leaving a diamond film at the bottom that can be easily detached and utilized for various applications.
Traditionally, synthetic diamond production requires "seed particles" for carbon atoms to attach and form a diamond. However, in this new method, trace amounts of silicon in the liquid metal aid in clustering carbon atoms, resulting in highly pure diamonds. While the specific metals used in the alloy can be varied, silicon appears to be crucial to the process.
The researchers plan to explore other liquid metal alloys and gases, as well as solid carbon sources, to evaluate their potential in diamond synthesis. Although it may be some time before we see diamonds grown in liquid metal vats in everyday jewelry, they are likely to find immediate use in industrial applications.
Diamonds have been synthesized in labs for decades, typically requiring extreme conditions of nearly 50,000 atmospheres of pressure and temperatures around 1,500 °C (2,732 °F). This new technique, however, successfully produces diamonds under standard pressure and relatively lower temperatures.
