bismuth strontium calcium copper oxide · wire
Bi-2212
The one high-temperature superconductor that can be made as a round, isotropic wire, and the reason it exists inside the strongest research magnets in the world.
Bi-2212 in numbers
- Transition temperature
- 85 K
- Made as
- wire
- Nitrogen line
- Above 77 K
What Bi-2212 runs in today
Round-wire inserts for magnets above 25 T.
Source: NHMFL high-field insert coil program; Larbalestier et al., Nature Materials 13, 375 (2014)
Why engineers choose Bi-2212
Every other high-temperature conductor is a tape, and a tape cannot be cabled and transposed the way a round strand can. Bi-2212 can. That single geometric fact is what puts it inside the highest-field magnets built. An insert coil wound from round wire behaves, mechanically and electrically, like the Nb3Sn and NbTi coils around it. The designer does not have to solve the tape problem a second time inside the same magnet.
Where Bi-2212 stops
The wire only reaches its published numbers after a reaction under high gas pressure, in a furnace built for the purpose. That is a capital item rather than a recipe, and the number of facilities on earth that can run it is the real ceiling on how much Bi-2212 magnet exists.
Process window
Needs overpressure heat treatment to reach its numbers.
Bi-2212 and the other wire conductors
Terms used on this page about Bi-2212
SuperMatics is a platform infrastructure company for superconducting devices: software that finds the material and the process, lab work that makes and measures it, and pilot manufacturing with industrial partners.If a conductor on this page stops short of what your device needs, tell us about it.