Editor’s Note
This article highlights a significant scientific achievement from Chinese researchers, who have successfully synthesized an ultra-hard diamond in the laboratory. This breakthrough material, inspired by a rare type found in meteorites, promises to advance industrial applications where extreme durability is required.
Chinese researchers have successfully synthesized a rare, ultra-hard diamond originally found in meteorites, which holds promise for advanced industrial applications.
A team of scientists from two Chinese universities has produced an ultra-hard, high-quality “super diamond” in the laboratory, with strength several times that of natural diamond.
The team behind this breakthrough believes their invention can find applications in critical fields, as diamonds are already widely used in industries such as cutting and polishing tools. While most natural and synthetic diamonds have a cubic structure, the ultra-hard diamond, known as lonsdaleite, possesses a hexagonal crystal structure.
To date, the hardest diamonds have only been found in impact craters, making them both rare and small. However, researchers led by Liu Bingbing, Yao Lingguang, and Zhu Shengcai from Jilin University and Sun Yat-sen University (Shenzhen) discovered that graphite forms a structure known as a “post-graphite phase.”
When compressed and heated under extremely high pressure, this leads to the formation of hexagonal diamond. The team’s findings were published earlier this month in the peer-reviewed journal *Nature Materials*.
The first ultra-hard diamond, lonsdaleite, was discovered in 1967 in the Diablo Canyon meteorite in Arizona. While scientists have reportedly found it challenging to artificially recreate the same diamond, the Chinese research team has proposed a method to synthesize nearly pure, well-crystallized hexagonal diamond from graphite.
Studies show that the synthetic diamond is of high quality with excellent physical properties. It is 40% harder than natural diamond and has higher thermal stability than nano-diamonds smaller than 100 nanometers.
They also noted that their findings provide valuable insights into the graphite-to-diamond transformation under high pressure and temperature, opening up opportunities for the manufacturing and use of this unique material.
This is not the first time this type of diamond has been developed in a laboratory. In 2021, a team of US researchers reported creating hexagonal diamonds large enough to measure their hardness using sound waves.
US scientists also found that hexagonal diamond could be harder than cubic diamond, making it an excellent choice for machining, drilling, or any application where cubic diamond is typically used.
Another author of the US study mentioned that hexagonal diamonds might be used in applications like engagement rings in the future. Their unique properties could make them an interesting alternative to traditional diamonds in certain markets.
Furthermore, Chinese researchers have previously achieved success in advancing diamond materials. Diamond is the hardest known natural substance, an excellent thermal conductor, but cannot carry an electrical charge. Last year, researchers from institutions including Zhengzhou University, Henan Academy of Sciences, Ningbo University, and Jilin University collaborated to successfully develop diamonds capable of conducting electricity.