Materials

World's strongest glass can scratch the surface of a diamond

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Scientists have developed a formidable new form of glass that is tough enough to scratch the surface of a diamond
Images show scratches in the surface of a natural diamond, created by a hard new material known as AM-III
Scientists have developed a formidable new form of glass that is tough enough to scratch the surface of a diamond

Material scientists in China experimenting with carbon in its many forms have conjured up a form of glass so hard that it can scratch the surface of a diamond. As reported by the South China Morning Post, the transparent material is also incredibly strong and has the ability to act as a semi-conductor, opening up some exciting possibilities in the realm of photovoltaics.

Called AM-III, the new material has some parallels with diamonds, both natural and man-made, in that it is formed primarily of carbon atoms. But where diamonds feature an arrangement of atoms and molecules in a perfect lattice structure, AM-III features a more disorganized structure where the atoms and molecules are misaligned, a kind of material known as amorphous.

Types of amorphous materials, or non-crystalline solids, include plastics, gels and, most famously, glass, but the lattermost is not something you'd normally associate with great hardness or strength. The scientists, from Yanshan University in China, sought to bring these characteristics to a glassy material through painstaking trial and error, experimenting with different arrangements of atoms and molecules, and by turning to soccer-ball-shaped molecules of carbon known as fullerenes.

We've seen material scientists study fullerenes to develop ignitable nanoparticles, advanced solar cells and further our knowledge of space, and the authors of the new study found they can also be used as the starting point for the formation of hardy amorphous materials. Fullerenes were subjected to increasing heat and pressure, causing them to be crushed and blended together, with the team carefully dialing up the heat and temperature into uncharted territory until AM-III was formed.

Images show scratches in the surface of a natural diamond, created by a hard new material known as AM-III

The new material proved to have a hardness of 113 GPa on a Vickers hardness test. For context, mild steel has a Vickers hardness of around 9 GPa, while naturally occurring diamonds rate at around 70 to 100 GPa. The team's comprehensive mechanical testing proved AM-III to be the hardest and strongest amorphous material known so far, and capable of scratching the surface of a diamond.

Further, the material was found to be semiconducting, with a bandgap range of 1.5 to 2.2 eV, similar to commonly used amorphous silicon. This mix of electronic and mechanical attributes makes AM-III an attractive proposition for scientists developing photovoltaic technologies that convert light into electricity, like those seen in solar cells.

The research was published in the journal National Science Review

Source: South China Morning Post

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5 comments
noteugene
Editor needs to think more proactive. Sounds like this material could be used for cutting head boring machines. Longer lasting drill bits, sanding paper? Someone's going to get rich.
P51d007
LOL, maybe they will call it "Scotty's transparent Aluminum"
Joy Phillip
Transparent Aluminum has already been invented. This would be called Decamole, after the ultra-hard glass tools shown in the Pliocene Saga by Julian May, starting with "The Many Colored Land". In there they made ultra sharp tools out of hardened glass, shatterproof, and using the ceramic's tendency to fracture in a sharp planes. This I think would be stronger than that. Solar Cells AND ultra-hard tools? The mining industry is going to go nuts.
Don Duncan
Already, SolarCity has the hardest, most efficient PV array. It has withstood hail the size of baseballs. But increased efficiency is worth chasing, developing. Home power generation, storage, backs up the grid, charges our cars, and will eliminate the tyranny of the govt. monopoly energy by creating personal energy independence. AM-iii could be a major breakthrough. Why did he CCP allow this story to get out?
Hugh Mcbroom
It sounds like this team has made meta stable compressed glassy carbon, they aren't the first to make this material, several groups have been independently working on it, each one has a different name for it, from compressed glassy carbon, meta stable amorphous carbon, quenched amorphous diamond and now AM - III. all the same material, all made by a pressure and heat treatment of glassy carbon, also known is vitreous carbon. The company i work for is exploring an application for this material as we speak. its semi conducting nature is new to me however.