Wikipedia
Vanadium-gallium
Vanadium-gallium (VGa) a superconducting alloy of vanadium and gallium often used for the high field insert coils of superconducting electromagnets.
Vanadium-gallium tape is used in superconducting magnets (17.5 teslas or 175,000 gauss). The structure of the superconducting A15 phase of VGa is similar to that of the more common NbSn and NbTi.
The high field characteristics can be improved by doping with high-Z elements such as Nb, Ta, Sn, Pt and Pb