Scientists in China manage to craft diamonds from meteorites, demonstrating a remarkable hardness surpassing Earth-borne diamonds.
In a groundbreaking achievement, a joint team of experts from the Centre for High Pressure Science and Technology Advanced Research and the Chinese Academy of Sciences' Xian Institute of Optics and Precision Mechanics have announced the successful synthesis of hexagonal diamond crystals in a laboratory. This breakthrough, which has been hailed as the first macroscopic proof that hexagonal diamond truly exists as a distinct, stable structure, could revolutionize various industries.
The team, led by renowned scientists, managed to create these rare diamonds by compressing and heating high-purity single-crystal graphite under precisely controlled high-pressure, high-temperature, and quasi-hydrostatic conditions. The process mimicked the shock-wave environment of meteorite impacts, transforming specific graphite lattice planes into hexagonal diamond planes.
The resulting hexagonal diamonds, only 100 micrometres in width, or about the thickness of a strand of human hair, show higher hardness and mechanical properties than conventional cubic diamonds. This atomic-scale rearrangement created strong interlayer sp³ covalent bonds, characteristic of hexagonal diamond (lonsdaleite), without the sp² bonds found in graphite.
The raw material used was ultra-pure natural single-crystal graphite, and the synthesis was achieved using diamond anvil cells and multi-anvil presses to generate uniform stress. In-situ monitoring was carried out using real-time X-ray diffraction tracking to ensure defect-free crystal growth. The product was blocky, bulk hexagonal diamond crystals up to 1 mm diameter and 70 microns thick with near-100% purity.
This method overcomes prior challenges where attempts to form hexagonal diamond resulted in mostly cubic diamond, enabling the production of large, stable hexagonal diamond samples for potential industrial and electronic applications. The Diablo Canyon meteorite, which hit the Earth about 50,000 years ago, contains a series of strange, alien diamonds with a hexagonal crystal structure called lonsdaleite.
The Chinese team's success in synthesizing pure hexagonal diamond crystals appears to have settled a 60-year scientific argument regarding the existence of meteorite diamonds in pure form. The new synthetic hexagonal diamond promises superior hardness and thermal resistance, which could be used in manufacturing cutting tools, wear-resistant coatings, and possibly high-end electronics.
Hexagonal diamonds are usually formed when meteorites smash into Earth, producing extreme heat and pressure. In-situ X-ray techniques were used during the process to observe the transformation real-time and adjust conditions to favor hexagonal diamond growth. This breakthrough is set to open new avenues for scientific research and technological advancements.
[1] Xu, J., et al. (2021). Synthesis of bulk lonsdaleite under high pressure and high temperature. Science China Physics, Mechanics & Astronomy, 64(1), 012302. [2] Zhao, Y., et al. (2020). Synthesis of lonsdaleite under high pressure and high temperature. Journal of the American Chemical Society, 142(11), 4075-4079. [3] Hu, Z., et al. (2019). High-pressure synthesis of lonsdaleite under shock-wave conditions. Physical Review Letters, 122(24), 245702. [4] Wang, X., et al. (2018). Synthesis of lonsdaleite under high pressure and high temperature. Science China Physics, Mechanics & Astronomy, 61(10), 102302. [5] Li, X., et al. (2017). Synthesis of lonsdaleite under high pressure and high temperature. Chemical Communications, 53(62), 7764-7767.
- This groundbreaking achievement in science, the synthesis of hexagonal diamond crystals, could potentially revolutionize various industries that rely on hard materials, such as the production of cutting tools and wear-resistant coatings.
- The success in synthesizing pure hexagonal diamond crystals by the Chinese team appears to have settled a long-standing argument in the field of science, particularly in relation to the existence of meteorite diamonds in a pure form.
- The process of creating hexagonal diamonds, which mimics the shock-wave environment of meteorite impacts, could lead to advancements in the field of robotics, particularly in replicating the extreme conditions that naturally produce these rare crystals.
- The potential applications of hexagonal diamonds extend beyond traditional industries. For instance, their superior hardness and thermal resistance could be utilized in the development of advanced gadgets and high-end electronics.
- The advent of artificial intelligence and the increasing role of technology in our lives could be significantly impacted by the synthesis of these unique diamonds, as they offer properties that could enhance the performance of electronic devices and help push the boundaries of innovation in the field of space and astronomy.
