Vanadium–gallium (V₃Ga) is a

superconducting Superconductivity is a set of physical properties observed in superconductors: materials where electrical resistance vanishes and magnetic fields are expelled from the material. Unlike an ordinary metallic conductor, whose resistance decreases g ...

alloy of

vanadium Vanadium is a chemical element; it has Symbol (chemistry), symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an ...

and

gallium Gallium is a chemical element; it has Chemical symbol, symbol Ga and atomic number 31. Discovered by the French chemist Paul-Émile Lecoq de Boisbaudran in 1875, elemental gallium is a soft, silvery metal at standard temperature and pressure. ...

. It is often used for the high field insert coils of superconducting electromagnets. Vanadium–gallium tape is used in the highest field magnets (

magnetic fields A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...

of ). The structure of the superconducting A15 phase of is similar to that of the more common . In conditions where the

magnetic field A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...

is higher than and the temperature is higher than , and see use. The main property of that makes it so useful is that it can be used in

up to about , while can only be used in fields up to about . The high field characteristics can be improved by doping with high-Z elements such as Nb, Ta, Sn, Pt and Pb.

Physical properties

has an A15 phase, which makes it extremely brittle. One must be extremely cautious not to over-bend the wire when handling it.

Superconducting properties

* Critical temperature (''T''_c): *

Upper critical field For a given temperature, the critical field refers to the maximum magnetic field strength below which a material remains superconducting. Superconductivity is characterized both by perfect conductivity (zero resistance) and by the complete expulsio ...

(''H''_c2): over .

Fabrication of superconductive wires or tapes

wires can be formed using solid-state

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

. File:V3GaTape1.jpg, superconducting tape ( cross section). A vanadium core is covered with layer, then bronze (stabilizing layer) and insulating layer. Critical current (, ), critical current density . File:V3GaWire.jpg, An example of a wire ( alloy) used in a superconducting magnet.

History

References

Superconductors Vanadium compounds Gallium alloys {{alloy-stub