Chinese scientists synthesize unprecedented super diamond material

In a groundbreaking achievement, researchers from Jilin University in northeastern China have synthesized an artificial form of hexagonal diamond, known formally as lonsdaleite, through a method that involves heating highly compressed graphite. This significant advancement in material science is documented in a recent study published in the journal Nature Materials. The new hexagonal diamond exhibits remarkable properties, including a hardness of 155 Giga Pascals (GPa) and thermal stability reaching up to 1,100°C, making it much tougher than natural diamonds, which usually have a hardness of around 100 GPa and thermal stability up to roughly 700°C. The potential applications of this new material are wide-ranging and could impact various industries that rely on diamond for drilling, machining, and even jewelry, such as engagement rings. Historically, hexagonal diamonds have been found in very limited and pure forms, primarily in meteorite impact craters, and their creation in a laboratory setting was unverified until now. Prior attempts at synthesizing hexagonal diamonds have faced challenges like low purity and small sample sizes, leaving many potential uses unexplored. This innovative synthesis was achieved by varying temperature and pressure during the heating process. Researchers Liu Bingbing and Yao Mingguang, leading the team, discovered that heating compressed graphite under specific conditions allows for the formation of well-structured, millimetre-sized blocks that comprise stacks of extremely small hexagonal diamond layers. Such structural stability and resilience indicate that this material could serve as a superior alternative to both conventional natural diamonds and previously synthesized forms of diamonds. The work by the Jilin University scientists not only paves the way for enhanced application in various industries but also improves our understanding of graphite-to-diamond conversion under elevated temperature and pressure. This study builds on previous research, including a 2021 project by Lawrence Livermore National Laboratory scientists, who had similarly succeeded in synthesizing hexagonal diamonds, highlighting ongoing advancements in this fascinating area of material science. Overall, the discoveries herald a new era of material innovation, presenting opportunities for the development of hexagonal diamonds in manufacturing, jewelry making, and other technological applications that require high durability and stability.