Superconductivity is the property of certain materials to conduct electricity without energy loss when they are cooled below a critical temperature. Superconductivity was discovered in mercury in 1911 by Heike Kamerlingh-Onnes.

Many materials have now been discovered to exhibit superconductivity at a wide range of temperature from nearly absolute zero (-273°C) to -150°C and even higher temperature at high pressures.

Wires made from an alloy of niobium and titanium enabled the construction of superconducting magnets. There are now many applications such as medical magnetic resonance imaging machines.

Alloys such as niobium-titanium and niobium-tin are known as low temperature superconductors (LTS). In 1986, copper-oxide materials were discovered to exhibited superconductivity at higher temperatures than these metals. These copper-oxide materials are starting to be used to make magnets. They are known as high-temperature superconductors (HTS).