Tuesday , October 19 2021

PC Revue | Slovak scientists are on the team who can find a key to the superconductivity of the ambient temperature


Superconductivity can only be achieved at very low temperatures and, therefore, all these devices require constant cryogenic cooling. This is also the main reason why we have not yet replaced conventional electric cables for those superconductors in our homes. The situation would change radically if we discovered material that would be superconductor at normal room temperature.

But, how on earth? This is not at all clear, because we still do not understand superconductivity well. In other words, we do not have a scientific theory that preaches with one hundred percent whether the material will be superconducting or not. Therefore, in their research, scientists rely on the test-error method, relying on similarities with those who already know.

In this sense, the ceramic materials based on copper and oxygen are the most significant family of superconductors discovered so far. It is the largest group of materials that reach the superconducting state at temperatures that are close to the liquid nitrogen temperature (= -77 aC). In the world of superconductivity, it is extraordinarily high, which is why it is known as ceramic superconductors of high temperature. Its enormous importance lies in the fact that all the materials that make up this group have the same distinctive characteristics.

Scientists believe that achieving the same characteristic traits in other materials will lead to the discovery of a new superconducting family. And they already have a hot candidate.It is a glass composed of atomic layers of silver and fluorine, AgF silver fluoride2.

The international team, made up of MTF STU researchers, several EU countries and the United States, has been researching silver and fluorine for a long time. In the last study, they indicated that the materials formed by the suitable combination of these elements are surprisingly similar to high temperature ceramic superconductors. In addition, they have the potential to overcome them. In January of this year, scientists presented their latest hot candidate, which has the potential to overcome superconductivity superconductivity of high temperature ceramic superconductors. His study was published by the prestigious journal of the American Academy of Sciences PNAS.

Detail of the polycrystalline sample AgF2, a hot candidate for the precursor of a new high-temperature superconducting family (Source: New Technologies Center of the University of Warsaw)

Scientists have been looking for a new layer material whose atomic layers are similar to a chessboard because this atomic chessboard is a structural feature characteristic of high temperature ceramic superconductors. This is copper and oxygen atoms (see below). When found in a material made of silver and fluorine (AgF2) focused on the behavior of electrons in it. They found that they behaved very much in a similar way to superconducting ceramic materials, that is to say, like extremely strong magnets.

But the biggest boost is that these interactions are much stronger if the layers are even more balanced than in the AgF2they are wrinkled Scientists believe that these enormous magnetic interactions in layered materials are the key to high temperatures of superconductivity. AgF2is the first serious candidate in which after doping it is expected to achieve a higher superconductivity temperature than in the famous ceramic superconductors of today.

You can read more information at PNAS Via Silver to cook the analogues.

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