Vanadium–gallium (V₃Ga) is a

superconducting Superconductivity is a set of physical properties observed in certain materials where Electrical resistance and conductance, electrical resistance vanishes and magnetic field, magnetic flux fields are expelled from the material. Any material e ...

alloy of

vanadium Vanadium is a chemical element with the 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 oxide layer ( pas ...

and

gallium Gallium is a chemical element with the symbol Ga and atomic number 31. Discovered by French chemist Paul-Émile Lecoq de Boisbaudran in 1875, Gallium is in group 13 of the periodic table and is similar to the other metals of the group (aluminiu ...

. 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 is a vector 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 to its own velocity and to ...

of 17.5 teslas). The structure of the superconducting A15 phase of V₃Ga is similar to that of the more common Nb₃Sn and Nb₃Ti. In conditions where the

magnetic field A magnetic field is a vector 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 to its own velocity and to ...

is higher than 8 Tesla and the temperature is higher than 4.2

Kelvin The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and phys ...

, Nb₃Sn and V₃Ga see use. The main property of V₃Ga that makes it so useful is that it can be used in

up to about 18 Tesla, while Nb₃Sn can only be used in fields up to about 15 Tesla.Reed, Richard P. Clark, Alan F. (1983). Materials at Low Temperatures – 13.9.3.2 Filament Diameter. ASM International. Retrieved from https://app.knovel.com/hotlink/pdf/id:kt00AEBP4A/materials-at-low-temperatures/filament-diameter The high field characteristics can be improved by doping with high-Z elements such as Nb, Ta, Sn, Pt and Pb

Physical Properties

V₃Ga has an

A15 phase The A15 phases (also known as β-W or Cr3Si structure types) are series of intermetallic compounds with the chemical formula ''A''3''B'' (where A is a transition metal and B can be any element) and a specific structure. The A15 phase is also one o ...

, 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) : ~14.2 Kelvin *

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 19 Tesla.

Fabrication of superconductive wires or tapes

V3Ga wires can be formed using

solid-state Solid state, or solid matter, is one of the four fundamental states of matter. Solid state may also refer to: Electronics * Solid-state electronics, circuits built of solid materials * Solid state ionics, study of ionic conductors and their use ...

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

File:V3GaTape1.jpg, V₃Ga superconducting tape (10×0.14 mm cross section). A vanadium core is covered with 15 µm V₃Ga layer, then 20 µm bronze (stabilizing layer) and 15 µm insulating layer. Critical current 180 A (19.2 tesla, 4.2 K), critical current density 20 kA/cm² File:V3GaWire.jpg, An example of a wire ( V₃ Ga alloy) used in a superconducting magnet.

History

References

Superconductors Vanadium compounds Gallium alloys {{alloy-stub