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 dissipator that prevents the temperature of semiconductors from rising. However, it is very difficult to synthesize these diamonds. 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 normal atmospheric pressure (1 atm) . In addition, 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 about 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 test preparation processes to be completed in 15 minutes in total, unlike existing machines that take 3 hours. The RSR-S machine is a machine that creates a liquid metal alloy by rapidly controlling temperature and pressure.
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 part of diamond, was released from the bottom surface. It was revealed that diamonds grow by diffusion of carbon from the base 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 ‘vacuum silicon color center’ structure in diamond was discovered by analyzing the light waves emitted by burning light on the material. 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 present, the structure of the silicon hollow color center has great magnetism, has high magnetic sensitivity, and exhibits quantum phenomena (quantum properties). Therefore, in the future, the development of nano-sized magnetic sensors and use in the field of quantum computers is expected.
Researcher Seong Won-kyung, corresponding author, said, “According to the results of this study, it has become possible to make diamonds more easily and in larger quantities. “By finding a way to replace the liquid metal alloy with another metal, we will open the way to synthesize diamond under a wider range of experimental conditions,” he said. express his expectations for continued research.
Director Rodney Ruoff, who led the research, said, “We have obtained the original technology for diamond synthesis that can be directly applied to key industries such as the semiconductor and machine industries. “Korea is expected to be able to rapidly expand application areas and lead related industries in the future.”
The research results were published on April 25 at midnight (Korean time) in the online edition of Nature (IF 64.8), the world’s most authoritative international academic journal.
Copyright ⓒ Acrofan All reserved.
