Type I superconductor
Encyclopedia
Superconductors cannot be penetrated by magnetic flux lines
(Meissner–Ochsenfeld effect). This Meissner state breaks down when the applied magnetic field is too large. Superconductors can be divided into two classes according to how this breakdown occurs. In Type-I superconductors, superconductivity is abruptly destroyed via a first order phase transition when the strength of the applied field rises above a critical value Hc. As such, they have only a single critical magnetic field at which the material ceases to superconduct, becoming resistive. Depending on the geometry of the sample, one may obtain an intermediate state described first by Lev Landau
consisting of a baroque pattern
of macroscopically large regions of normal material carrying a magnetic field mixed with regions of superconducting material containing no field. Elementary
superconductors, such as aluminium
and lead
are typical Type-I superconductors. The origin of their superconductivity is explained by BCS theory
.
This type of superconductivity is normally exhibited by pure metals, e.g. aluminium, lead or mercury.
Magnetic flux
Magnetic flux , is a measure of the amount of magnetic B field passing through a given surface . The SI unit of magnetic flux is the weber...
(Meissner–Ochsenfeld effect). This Meissner state breaks down when the applied magnetic field is too large. Superconductors can be divided into two classes according to how this breakdown occurs. In Type-I superconductors, superconductivity is abruptly destroyed via a first order phase transition when the strength of the applied field rises above a critical value Hc. As such, they have only a single critical magnetic field at which the material ceases to superconduct, becoming resistive. Depending on the geometry of the sample, one may obtain an intermediate state described first by Lev Landau
Lev Landau
Lev Davidovich Landau was a prominent Soviet physicist who made fundamental contributions to many areas of theoretical physics...
consisting of a baroque pattern
Husimi Q representation
The Husimi-Q distribution is a mathematical tool used in physics, and was introduced in 1940. The Q-representation is a quasi-probability distribution commonly used in quantum mechanics and also to represent the quantum state of light. It is used in the field of quantum optics and particularly...
of macroscopically large regions of normal material carrying a magnetic field mixed with regions of superconducting material containing no field. Elementary
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
superconductors, such as aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
and lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
are typical Type-I superconductors. The origin of their superconductivity is explained by BCS theory
BCS theory
BCS theory — proposed by Bardeen, Cooper, and Schrieffer in 1957 — is the first microscopic theory of superconductivity since its discovery in 1911. The theory describes superconductivity as a microscopic effect caused by a "condensation" of pairs of electrons into a boson-like state...
.
This type of superconductivity is normally exhibited by pure metals, e.g. aluminium, lead or mercury.
See also
- Conventional superconductorConventional superconductorConventional superconductors are materials that display superconductivity as described by BCS theory or its extensions.Critical temperatures of some simple metals:ElementTc Al1.20Hg4.15Mo0.92Nb9.26Pb7.19...
- Covalent superconductorsCovalent superconductorsCovalent semiconductors are such solids as diamond, silicon, germanium, silicon carbide and silicon-germanium where atoms are linked by covalent bonds. Most of those materials, at least in their bulk form, are well studied and rarely hit the front pages of the top scientific journals in the last...
- List of superconductors
- High-temperature superconductivityHigh-temperature superconductivityHigh-temperature superconductors are materials that have a superconducting transition temperature above . From 1960 to 1980, 30 K was thought to be the highest theoretically possible Tc...
- Room temperature superconductorRoom temperature superconductorA room-temperature superconductor is a material yet to be discovered which would be capable of exhibiting superconducting properties at operating temperatures above 0° C . This is not strictly speaking "room temperature" A room-temperature superconductor is a material yet to be discovered...
- SuperconductivitySuperconductivitySuperconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum...
- Superconductor classificationSuperconductor classificationSuperconductors can be classified in accordance with several criteria that depend on our interest in their physical properties, on the understanding we have about them, on how expensive is cooling them or on the material they are made of....
- Technological applications of superconductivityTechnological applications of superconductivitySome of the technological applications of superconductivity include:* the production of sensitive magnetometers based on SQUIDs* fast digital circuits ,...
- Timeline of low-temperature technologyTimeline of low-temperature technologyThe following is a timeline of low-temperature technology and cryogenic technology .-16th century BCE – 17th century CE :...
- Type-1.5 superconductivity
- Type-II superconductorType-II superconductorA Type-II superconductor is a superconductor characterized by the formation of vortex lattices in magnetic field. It has a continuous second order phase transition from the superconducting to the normal state within an increasing magnetic field....
- Unconventional superconductorUnconventional superconductorUnconventional superconductors are materials that display superconductivity which does not conform to either the conventional BCS theory or the Nikolay Bogolyubov's theory or its extensions....