When Chinese materials scientists experimented with various forms of carbon, they discovered a very hard glass that could scratch the surface of diamonds. As reported by the South China Morning Post, this transparent material is also very strong and can act as a semiconductor, opening up some exciting possibilities in the photovoltaic field.

This new material, called AM-III, has some similarities with natural and man-made diamonds because it is mainly formed of carbon atoms. However, diamond is characterized by the arrangement of atoms and molecules into a perfect lattice structure, while AM-III has a more chaotic structure in which the atoms and molecules are not aligned. This is a material called amorphous.

Types of amorphous materials or non-crystalline solids include plastics, gels, and the most famous glass, but the latter is usually not something you usually associate with high hardness or strength. Scientists from Yanshan University in China have tried to bring these characteristics to glass materials through painstaking trial and error, trying different arrangements of atoms and molecules, and by turning to football-shaped carbon molecules called fullerenes.

We have seen materials scientists researching fullerenes to develop combustible nanoparticles, advanced solar cells, and to further understand our space, and the authors of new research have discovered that they can also be used as starting points for the formation of cold-resistant amorphous materials. Fullerenes are subjected to increasing heat and pressure, causing them to be crushed and mixed together. The team carefully adjusted the heat and temperature to unknown areas until AM-III was formed.

In the Vickers hardness test, the hardness of the new material was 113 GPa. For context, the Vickers hardness of mild steel is about 9 GPa, while the hardness of natural diamond is about 70 to 100 GPa. The team’s comprehensive mechanical tests proved that AM-III is the hardest and strongest amorphous material known to date, capable of scratching the surface of diamonds.

In addition, the material was found to be semiconducting, with a band gap ranging from 1.5 to 2.2 eV, similar to commonly used amorphous silicon. This mix of electrical and mechanical properties makes AM-III an attractive proposal for scientists developing photovoltaic technology that converts light into electrical energy, as seen in solar cells.

The research was published in the journal National Science Review. 

Source: South China Morning Post