Chinese Scientists Synthesize Hexagonal Diamond Harder Than Natural Diamonds
Chinese researchers have successfully synthesized hexagonal diamond, a form harder than natural cubic diamonds, potentially revolutionizing industrial applications.
Chinese scientists have successfully synthesized hexagonal diamond, also known as lonsdaleite, a rare carbon allotrope previously found only in meteorite impact sites. This form of diamond exhibits a hexagonal crystal structure, differing from the cubic structure of natural diamonds.
The research team, led by physicist Chongxin Shan from Zhengzhou University, subjected highly oriented graphite to extreme conditions—pressures of 20 gigapascals (approximately 200,000 times atmospheric pressure) and temperatures between 1,300 and 1,900 degrees Celsius. This process resulted in the formation of millimeter-sized hexagonal diamond crystals.
Structural analysis using X-ray diffraction and electron microscopy confirmed the purity and hexagonal arrangement of the synthesized diamonds. Hardness tests indicated that these hexagonal diamonds possess a Vickers hardness of approximately 114 gigapascals, slightly surpassing the 110 gigapascals typical of natural cubic diamonds.
The successful laboratory synthesis of hexagonal diamond opens new avenues for developing superhard materials with potential applications in cutting tools, drilling equipment, and advanced electronics.