The Slovaks created an unusual material. They found it between the layers of graphene
At Danubia Nanotech, scientists are trying to create high-quality graphene without defects. Graphene is a two-dimensional material made of carbon, which is also the strongest material in the world. To check for flaws in the graphene structures, they use a microscope that can resolve things down to the size of atoms. During one such check, they also discovered the two-dimensional structure of copper iodide.
“At that moment, we had no idea that this structure could not be prepared at room temperature and normal pressure,” says Skákalová.
Copper iodide has several forms. However, the observed two-dimensional form exists only at a high temperature of around four hundred degrees Celsius. “That’s why it’s basically still unexplored,” adds the scientist.
When preparing graphene, however, the scientists did not use any extreme temperatures; they wondered how copper iodide could be formed under normal laboratory conditions.
The explanation was following: The two-dimensional layer was stable because it was encapsulated between two layers of graphene. Graphene is impermeable even to small atoms. Therefore, once an atom, molecule or 2D layer is encapsulated in a graphene sandwich, it remains stable there.
“We reconstructed a probable scenario of accidental synthesis and proposed a chemical procedure for its production in principle in any large quantity,” says Skákalová. The preparation of the material is described in a study in the scientific journal Advanced Materials (DOI: doi.org/10.1002/adma.202106922 ), on which Danubia NanoTech worked together with scientists from the universities of Vienna, Tübingen and Antwerp.
With the discovered chemical process, Danubia NanoTech can create unlimited amounts of copper iodide at room temperatures.
At the same time, they can also create many other two-dimensional materials that can be used in the assembly of electronic components of the future. At Danubia Nanotech, they have already prepared several 2D compounds with different properties.
“The ferromagnetic 2D layers of nickel iodide and exotic layers with elements of bismuth, europium or gold and silver are particularly interesting,” adds Skákalová.
Renáta Zelná, 22. dec 2021