기초과학연구원(IBS, 원장 노도영) 다차원 탄소재료 연구단 로드니 루오프 연구단장 연구팀은 갈륨, 철, 니켈, 실리콘으로 구성된 액체 금속 합금을 이용하여 1기압에서 다이아몬드를 합성하는 데 세계 최초로 성공했다.

▲Diamond crystals made using the RSR-S device
Synthesis in 15 minutes at 1,025℃ and 1 atm using 'RSR-S'
Expected applications include nano-sized magnetic sensors and quantum computers
The paradigm that most diamonds are produced under high temperature and high pressure conditions has been completely shattered. This is the first method developed to synthesize diamonds at atmospheric pressure (1 atm), which is the pressure around us.
A research team led by Rodney Ruoff, head of the Center for Multidimensional Carbon Materials at the Institute for Basic Science (IBS, President Do-Young Noh), announced on the 25th that they had succeeded in synthesizing diamond at 1 atmosphere of pressure for the first time in the world 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 widely used as a heat conductor in electronic devices and as a heat sink to prevent temperature rise in semiconductors.
On the other hand, it is quite difficult to synthesize such diamonds.
This is because most diamonds are synthesized only under high temperatures of up to 1,300 to 1,600 degrees Celsius and high pressures of 50,000 to 60,000 times the standard atmospheric pressure (1 atm).
Additionally, due to the size limitations of the pressure cell required to maintain high temperature and high pressure conditions, the size of synthetic diamonds is limited to approximately 1 cubic centimeter.
The IBS research team has completely broken the existing diamond synthesis paradigm by synthesizing diamond for the first time under conditions of 1,025 degrees Celsius and 1 atm of pressure.
First, the research team developed a device called 'RSR-S' that can rapidly heat and cool, enabling the entire experimental preparation process to be completed in just 15 minutes, unlike existing devices that take 3 hours.
The RSR-S device is a device that creates a liquid metal alloy by rapidly controlling temperature and pressure, and was used to adjust hundreds of parameters to find the optimal temperature, pressure, and liquid metal alloy ratio conditions for growing diamonds.
The research team created a liquid metal alloy composed of 77.75% gallium, 11.00% nickel, 11.00% iron, and 0.25% silicon from methane and hydrogen.
And on the lower surface, we confirmed that carbon, a component of diamond, was diffusing.
It was discovered that diamonds grow by carbon diffusion beneath a liquid metal alloy at a temperature of 1,025 degrees and a pressure of 1 atm.
Additionally, the 'silicon vacancy color center' structure within diamond was discovered by analyzing the wavelength of light emitted by shining light on the material through an experiment called 'photoluminescence spectroscopy'.
This structure is one in which silicon, one of the components of a liquid metal alloy, is sandwiched between diamond crystals made entirely of carbon.
At this time, the silicon vacancy color center structure has a quantum-sized magnetism, high magnetic sensitivity, and quantum phenomena (quantum characteristics). Therefore, in the future, it is expected to be applied to the development of nano-sized magnetic sensors and the field of quantum computers.
Co-corresponding author and researcher Seong Won-gyeong said, “Based on the results of this study, we can now create diamonds more easily and on a larger scale. We will find a way to replace the composition of the liquid metal alloy with other metals, which will open the way to synthesizing diamonds under a wider range of experimental conditions,” expressing his expectations for follow-up research.
Rodney Ruoff, the research director who led the research, said, “We have acquired the basic technology for diamond synthesis that can be directly applied to major industries such as semiconductors and machinery. We expect that Korea will be able to rapidly expand the application areas and lead related industries in the future.”
The research results were published in the online edition of the world's most prestigious international academic journal, 'Nature (IF 64.8),' at 0:00 (Korean time) on April 25.