Scientists from the University of Edinburgh, in collaboration with experts from the University of Bayreuth, Germany, and the University of Linköping, Sweden, have made a groundbreaking discovery of a new ultra-tough material called carbon nitrides. This material has surpassed the hardness of cubic boron nitride, previously the second hardest substance after diamonds.
The team, led by the Centre for Science at Extreme Conditions at the University of Edinburgh, uncovered these carbon nitride materials, exhibiting properties that have been the subject of material science aspirations since the 1980s due to their hardness comparable to diamonds. Dr. Dominique Laniel, a Future Leaders Fellow at the University of Edinburgh, expressed astonishment at producing materials that researchers have been dreaming of for decades and emphasized their potential industrial applications.
The synthesis of carbon nitrides involves specific procedures where carbon and nitrogen precursors react under precise conditions. The resulting material features a three-dimensional framework of CN4 tetrahedra. Carbon-rich compounds and nitrogen-containing materials, such as tI14-C3N4, hP126-C3N4, and tI24-CN2, serve as precursors, generated within specialized diamond anvil cells using laser heating techniques. These conditions involve high temperatures and pressures, with the diamond anvil cell acting as a crucial tool for creating different forms of carbon nitrides.
The study, employing synchrotron single-crystal X-ray diffraction, determined and refined the structures of these compounds. The precursors underwent extreme conditions, with pressures ranging from 70 to 135 gigapascals and temperatures exceeding one and a half thousand degrees Celsius. The compounds retained their diamond-like qualities when returning to ambient pressure and temperature conditions, opening doors for multifunctional applications.
This breakthrough has paved the way for industrial uses, including protective coatings for cars and spaceships, high-endurance cutting tools, solar panels, and photodetectors. Further computational and experimental investigations suggest additional characteristics such as photoluminescence and high energy density. Dr. Florian Trybel from the University of Linköping highlighted the outstanding multi-functionality of these materials and their recovery from synthesis pressures equivalent to conditions found deep within the Earth’s interior, anticipating new possibilities in the field.
By Impact Lab