World’s first successful diamond production at 1 atm

The paradigm that most diamonds are produced under high temperature and pressure conditions has been completely broken. That is, the first method of synthesizing diamonds at atmospheric pressure (1 atmosphere), which is the atmospheric pressure around us, was developed. The research team of Rodney Ruoff, director of the Center for Multidimensional Carbon Materials at the Institute for Basic Science (IBS, Director Doyoung Noh), was the first in the world to succeed in synthesizing diamond at 1 atm using a liquid metal alloy composed of gallium, iron, nickel, and silicon.

Diamond is a carbon material with excellent thermal conductivity, hardness, and chemical resistance, and is very useful as a heat conductor in electronic devices and a heat dissipation device that prevents the temperature of semiconductors from rising. However, synthesizing these diamonds is quite difficult. This is because most diamonds are synthesized only under high temperatures approaching 1,300 to 1,600 degrees Celsius and high pressure conditions reaching 50,000 to 60,000 times standard atmospheric pressure (1 atm). Additionally, due to limitations in the size of the pressure cell to maintain high-temperature and high-pressure conditions, the size of diamond that can be synthesized is limited to approximately 1 cubic centimeter.

The IBS research team synthesized diamond for the first time at a temperature of 1,025 degrees and a pressure of 1 atmosphere, completely breaking the existing diamond synthesis paradigm. First, the research team self-produced a device called ‘RSR-S’ that can heat and cool quickly, allowing all experiment preparation processes to be completed in a total of 15 minutes, unlike existing devices that take 3 hours. The RSR-S device is a device that creates liquid metal alloy by quickly controlling temperature and pressure. It was used to adjust hundreds of parameters to find the optimal temperature, pressure, and liquid metal alloy ratio conditions to grow diamonds.

The research team created a liquid metal alloy consisting of 77.75% gallium, 11.00% nickel, 11.00% iron, and 0.25% silicon from methane and hydrogen. And it was confirmed that carbon, a diamond component, was diffused from the lower surface. It was revealed that diamonds grow by carbon diffusion from the bottom of the liquid metal alloy at a temperature of 1025 degrees and a pressure of 1 atmosphere.

In addition, through an experiment called ‘photoluminescence spectroscopy’, the ‘silicon void color center’ structure in diamond was discovered by analyzing the wavelengths of light emitted by shooting light at the material. This structure is one in which silicon, one of the components of liquid metal alloy, is sandwiched between diamond crystals made only of carbon. At this time, the silicon void color center structure has quantum-sized magnetism, has high magnetic sensitivity, and exhibits quantum phenomena (quantum characteristics). Therefore, in the future, development of nano-sized magnetic sensors and application in the field of quantum computers are expected.

Researcher Seong Won-kyung, co-corresponding author, said, “Based on the results of this study, it has become possible to make diamonds more easily and in larger sizes. “By finding a way to replace the composition of the liquid metal alloy with another metal, we will open the way to synthesize diamond under a wider range of experimental conditions,” he said, expressing his expectations for follow-up research.

Director Rodney Ruoff, who led the research, said, “We have acquired the original technology for diamond synthesis that can be directly applied to major industries such as semiconductor and machinery industries. “It is expected that Korea will be able to quickly expand application areas and lead related industries in the future.”
The research results were published on April 25th at midnight (Korean time) in the online edition of Nature (IF 64.8), the world’s most authoritative international academic journal.

Copyright ⓒ Acrofan All Right Reserved.