Super hard diamond glass with highest thermal conductivity

Experts use pressure to transform a carbon material into a new type of glass that has the potential to be mass-produced with a wide range of applications.

An international research team has synthesized a new type of ultra-hard carbon glass with abundant potential for applications in devices and electronics. This is the hardest glass with the highest thermal conductivity of all glass materials available today. The new study was published in the journal Nature on November 24.

Low-temperature and high-pressure processing in the lab can turn buckyball materials into super-hard diamond glass. (Photo: Shutterstock)

The way atoms are chemically bonded together and their structural arrangement determine the physical properties of a material, including those that can be seen with the naked eye and those that are only revealed. through scientific analysis.

Carbon leads the way in its ability to form stable structures, either alone or in combination with other elements. Some forms of carbon have a sophisticated organization with repeating latticework. Others have a more chaotic order, called amorphous. The type of bond that binds the carbon-based material determines the stiffness. For example, soft graphite has two-way bonds and hard diamond has three-way bonds.

"Synthesis of amorphous carbon materials with three-dimensional bonds has been a long-standing goal. The key is to find a suitable starting material for transformation by pressure," said Yingwei Fei, an expert at the Institute of Science and Technology. Carnegie, a member of the research team, explains.

"For decades, researchers at Carnegie have been at the forefront of this field. We use laboratory techniques to generate extreme pressures, which in turn create new materials or simulate things. events like those deep inside the planets," said Richard Carlson, director of the Planetary and Earth Laboratory at the Carnegie Institution for Science.

Due to its high melting point, diamond cannot be used as a starting material for the synthesis of diamond-like glasses. However, the team led by experts Bingbing Liu and Mingguang Yao at Jilin University made the breakthrough by using a form of carbon consisting of 60 molecules folded into a hollow sphere. This material is called buckyball and has won the prestigious Nobel Prize.

In the new study, the team heated it just enough to collapse the buckyball's soccer-ball-like structure, causing disorder, and then turned the carbon into crystalline diamond under pressure. The team used a large-capacity press to synthesize the diamond-like glass. They confirmed its properties using a variety of advanced techniques specialized for understanding the atomic structure.

"Glass with such superior properties opens the door to new applications. We can synthesize a new type of super-hard diamond glass at relatively low temperatures. This makes mass production easier. should be more feasible," Fei said.