A superconductor, when cooled to a certain temperature, no longer offers resistance to the passage of electric current.
Superconductor is an adjective applied to those materials that, when cooled, no longer resist the passage of electric current. Thus, at a certain temperature, the material becomes a perfect electrical conductor .
Superconductivity is therefore a property of some materials. Substances that can act as superconductors are those that, under specific conditions, can conduct current without energy loss or resistance .
The contribution of Heike Kamerlingh Onnes
In 1911 , the scientist Heike Kamerlingh Onnes discovered that metallic conductors lose resistivity when the temperature decreases. When the temperature drops below a temperature classified as critical , the resistance is completely eliminated.
In this way, electric current can flow indefinitely through the superconductor even without the action of a power supply.
Characteristics of a superconductor
It is important to note that superconducting materials can be classified according to several relevant criteria, such as the following:
-If we take into account their material, we can say that there are four large groups: ceramics, alloys, those with carbon structures and pure elements.
-Based on their physical behavior, it can be determined that there are two types of superconductors: type I, which have the particularity of being able to change from the superconducting state to the normal state very quickly, and type II. The latter are those that have, as scientists call it, two critical magnetic fields.
-Depending on their critical temperature, there are two types: high temperature, if it is above 77k, and low temperature, which are characterized by having it below the aforementioned 77k.
-Finally, another existing classification is the one based on the theory that explains them and determines that they can be conventional, whose origins are in the phonons, and non-conventional, when the cited origin they have is different from those cited.
Aluminum is a superconductor.
The case of aluminium and tin
Aluminum and tin are two examples of superconducting materials. The materials are often cooled with liquid helium to allow them to reach the critical temperature mentioned above. When the material becomes superconducting, it can be used to develop circuits and electromagnets .
Currently, among the most useful and interesting applications of the aforementioned superconducting materials are the following:
-In the medical field, they have been used to treat aneurysms without surgery, to remove tumors, and even to correct arteries that have suffered damage.
-In the scientific field, they have been used and continue to be used to undertake studies of plant growth.
Superconductors in motors and energy storage
In the future, superconductors are expected to be used to build electric motors and create equipment that can store energy , among other applications.
Finally, it should be noted that high-temperature superconductors are materials that have a critical temperature higher than the boiling point of nitrogen or that do not comply with the BCS theory (developed in 1957 to explain superconductivity).