Explore the five most common types of superconductors: conventional, high-temperature, iron-based, heavy fermion, and organic ones.
1. Conventional Superconductors
The most commonly recognized type of superconductors are conventional superconductors. These are typically composed of elemental metals or simple alloys, such as aluminum or niobium. They were the first discovered, and they superconduct at low temperatures, usually below 30K. The phenomenon can be explained using Bardeen-Cooper-Schrieffer (BCS) theory.
2. High-Temperature Superconductors (HTS)
High-Temperature Superconductors, often abbreviated as HTS, are a significant group. These materials can achieve superconductivity at temperatures as high as 138K. Copper-oxide ceramics (cuprates) are the most common materials in this category. These superconductors have layered structures, which is believed to be essential for their high transition temperatures.
3. Iron-Based Superconductors
Iron-based superconductors were discovered in 2008 and are another type of high-temperature superconductors. These materials, like HTS, have layered structures but with FeAs or FeSe layers. They can superconduct at temperatures up to 58K.
4. Heavy Fermion Superconductors
Heavy fermion superconductors consist of compounds of rare earth or actinide elements with transition metals. The term “heavy fermion” arises from the effective large mass of the electrons due to strong electron-electron interactions. These superconductors show unconventional superconductivity, often associated with magnetic fluctuations.
5. Organic Superconductors
Organic superconductors are composed primarily of carbon, hydrogen, and other non-metallic elements. Despite their relatively low superconducting transition temperatures (below 15K), they are notable for being among the few known examples of superconductivity in a system with reduced dimensionality.
