This new material, AM-III, is the strongest and hardest new material in the world . It is the work of a team of researchers from Yanshan University in Hebei province (China), who were able to create a new transparent amorphous material that is so strong and hard that it can scratch diamonds. Also, this high-tech glass has a semiconductor bandgap, which makes it quite interesting for solar panels.
“Extensive mechanical testing shows that synthesized AM-III carbon is the toughest and strongest amorphous material known to date, which can scratch diamond crystal and approach its strength. The AM carbon materials produced combine outstanding mechanical and electronic properties, and can potentially be used in photovoltaic applications that require ultra-high strength and wear resistance, ”the authors of the new study wrote in the National Science Review.
The material, provisionally named AM-III, rated 113 gigapascals (GPA) in the Vickers hardness test . Vickers hardness, a measure of the hardness of a material, is calculated from the size of an impression produced under load by a pyramid-shaped diamond indenter. For comparison, mild steel or carbon steel has a Vickers hardness of around 9 GPa , while natural diamonds have a rating of around 70 to 100 GPa.
The new material has some parallels to diamonds, both natural and man-made, as it is made up mainly 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 type of material known as amorphous.
Through painstaking trial and error, the scientists discovered that fullerenes – a molecule made of carbon that can take on a geometric shape similar to a sphere – can also be used as a starting point for the formation of resistant amorphous materials. The fullerenes were subjected to increasing heat and pressure, causing them to crush and mix until AM-III was formed. They spent more than 12 hours gradually increasing the heat and pressure to maximum, and they spent the same amount of time letting the material cool slowly.
If they had taken the process too far and pushed the carbon into an overly organized arrangement, the glass would have weakened and lost its semiconductor properties. The end result, thankfully, was glass that scored higher than natural diamonds in a strength test and could easily scratch the surface of a diamond – an incredible achievement for a material we normally associate with breakage.
AM-III, for example, is almost as efficient a semiconductor as silicon. This ability to transfer electrical current at will makes it a strong candidate for use in photoelectric devices, including weapons, that must operate in extreme environments such as high pressure and temperatures.
“The emergence of this type of ultra-tough, ultra-strong semiconductor amorphous carbon material offers excellent candidates for the most demanding practical applications,” commented the authors of the work.
Referencia: Discovery of carbon-based strongest and hardest amorphous material
Shuangshuang Zhang, Zihe Li, Kun Luo, Julong He, Yufei Gao, Alexander V Soldatov, Vicente Benavides, Kaiyuan Shi, Anmin Nie, Bin Zhang … Show more
National Science Review, nwab140, https://doi.org/10.1093/nsr/nwab140
Published: 05 August 2021
