The superconducting materials They are those that, under certain conditions, have the ability to conduct electrical current without any resistance or loss of energy. For instance: Mercury, Lithium, Titanium, Cadmium.
The resistance of a superconductor, unlike ordinary conductors like gold and silver, drops sharply to zero when the material cools below its critical temperature – an electrical current flowing in a spiral of superconducting wire It can circulate indefinitely without a power supply.
Discovery of superconductivity
Superconductivity is a phenomenon linked to quantum mechanics and was discovered in 1911 by the Dutch scientist Heike Kamerlingh Onnes, who observed that the electrical resistance of mercury disappeared when it was cooled to a temperature of 4 Kelvin (-269 ºC).
Superconductivity normally occurs at low temperatures, although for a conductor to function as a superconductor, it is also necessary that a critical current or magnetic field is not exceeded.
The first superconductors discovered operated at critical temperatures of around 250 ° C below zero. High-temperature superconductors were discovered in the 1980s, which had a critical temperature of about 179 degrees Celsius below zero. This greatly made the study of materials cheap and also opened the door to the existence of superconductors at room temperature.
Classification of superconducting materials
If a weak external magnetic field is applied to a superconductor, it repels it. When the magnetic field is high, the material is no longer superconducting. This critical field stops a material from being superconducting.
An additional classification that is made regarding these conductors is the one that divides them according to their ability to completely shield an external magnetic field. Type I superconductors completely prevent the penetration of external magnetic fields, while type II superconductors are imperfect in the sense that they allow the magnetic field to penetrate inside.
Uses and applications of superconducting materials
Until now, the main utility of superconductors is the production of very strong magnetic fields without loss of energy. Thus, they have applications in medicine, in the construction of particle accelerators and the control of nuclear reactors, among other things. The development of superconductors also makes it possible to advance in the study of faster computers with greater memory, high-speed magnetic levitation trains and the possibility of generating electrical energy more efficiently.
Furthermore, superconductors are used in physics laboratories for research purposes, for example in nuclear magnetic resonance studies and high-resolution electron microscopy.
Methods of obtaining superconducting materials
Obtaining superconducting materials is subject, for the moment, to extremely low temperatures, which is why elements such as helium or liquid nitrogen are usually used.
Examples of superconducting materials
| Carbon (superconducting in a modified form) | Cadmium | Zirconium |
| Chromium (superconducting in a modified form) | Sulfur (superconducting under high pressure conditions) | Uranium |
| Lithium | Selenium (superconducting under high pressure conditions) | Niobium |
| Beryllium | Osmium | Molybdenum |
| Titanium | Strontium (superconducting under high pressure conditions) | Ruthenium |
| Vanadium | Barium (superconducting under high pressure conditions) | Rhodium |
| Oxygen (superconducting under high pressure conditions) | Boron (superconducting under high pressure conditions) | Calcium (Superconducting under high pressure conditions) |
| Iridium | Tungsten | Silicon (Superconducting under high pressure conditions) |
| Technetium | Tantalum | Americium |
| Rhenium | Phosphorus (superconducting under high pressure conditions) | Aluminum |
| Indian | Mercury | Gallium |
| Thallium | Arsenic (superconducting under high pressure conditions) | Tin |
| Zinc | Bromine (superconducting under high pressure conditions) | Lead |
| Bismuth |