Bi2Sr2CaCu20x (2212) superconductors have been fabricated into silver(Ag)-sheathed single filament, mul tifilament and Wire - in-Tube (WIT) tapes. Calc ining, anneal ing and s intering conditions have been studied to improve the critical current density Jc(B,4.2K) at high magnetic field (B). The optimization is discussed and resulting properties are related to the microstructure of the superconductor. Superconductor Jc-1-5xl04 A/cm2 has been obtained in fields >20 Teslas at 4.2K in both single and multifilamentary tapes. Furthermore, the dependence of Jc upon mechanical strain (ϵ) has been investigated. No pre-straining of the superconductor occurred in any of the samples, most likely due to yielding of the Ag sheath. Although strain resistance was good in all samples, the WIT tapes were significantly more resistant than the single filament tapes. For the single filament tapes, ϵirr-0.24%, while for the WIT tapes, ϵirr-0.36%, where ϵirr is the irreversible strain limit.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering