Niobium–titanium (Nb-Ti) is an alloy of niobium and titanium, used industrially as a type II superconductor wire for superconducting magnets, normally as Nb-Ti fibres in an aluminium or copper matrix.
Nb-Ti wires coming out of an LHC dipole magnet.
Image: Cross section of preform superconductor cable
Image: Cross section of preform superconductor cable 2
Image: Cross section of preform superconductor cable 3
In superconductivity, a type-II superconductor is a superconductor that exhibits an intermediate phase of mixed ordinary and superconducting properties at intermediate temperature and fields above the superconducting phases.
It also features the formation of magnetic field vortices with an applied external magnetic field.
This occurs above a certain critical field strength Hc1. The vortex density increases with increasing field strength. At a higher critical field Hc2, superconductivity is destroyed. Type-II superconductors do not exhibit a complete Meissner effect.
Quantum vortices in a 200-nm-thick YBCO film imaged by scanning SQUID microscopy