Superconductivity
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Superconductivity is a set of physical properties observed in superconductors: materials where electrical resistance is exactly zero and magnetic fields are expelled from the material. Unlike an ordin
A high-temperature superconductor levitating above a magnet. A persistent electric current flows on the surface of the superconductor, acting to exclude the magnetic field of the magnet (Meissner effect). This current effectively forms an electromagnet that repels the magnet.
Heike Kamerlingh Onnes (right), the discoverer of superconductivity. Paul Ehrenfest, Hendrik Lorentz, Niels Bohr stand to his left.
Top: Periodic table of superconducting elemental solids and their experimental critical temperature (T) Bottom: Periodic table of superconducting binary hydrides (0–300 GPa). Theoretical predictions indicated in blue and experimental results in red
Electric cables for accelerators at CERN. Both the massive and slim cables are rated for 12,500 A. Top: regular cables for LEP; bottom: superconductor-based cables for the LHC
High-temperature superconductivity is superconductivity in materials with a critical temperature above 77 K, the boiling point of liquid nitrogen. They are "high-temperature" only relative to previous
Superconductivity
…as a refrigerant. Such a high transition temperature is theoretically impossible for a conventional superconductor, leading the materials to be termed high-temperature superconductors. The cheaply available coolant liquid nitrogen boils at 77 K (−196 °C) and thus the existence of superconductivity at higher temperatures than this…
A sample of bismuth strontium calcium copper oxide (BSCCO), which is currently one of the most practical high-temperature superconductors. Notably, it does not contain rare earths. BSCCO is a cuprate superconductor based on bismuth and strontium. Thanks to its higher operating temperature, cuprates are now becoming competitors for more ordinary niobium-based superconductors, as well as magnesium diboride superconductors.
Small magnet levitating above a high-temperature superconductor cooled by liquid nitrogen: this is a case of Meissner effect.