Fabrication of Bi-(Pb)-Sr-Ca-Cu-O mono- and multifilamentary superconductors and improvement in critical current density

Publisher Website
Google Scholar
Abstract
The Bi‐(Pb)‐Sr‐Ca‐Cu‐O superconductor has been fabricated into tapes without sheathing and into multifilamentary wires and tapes with Ag sheathing. Metallurgical studies as well as measurements have been made for them. Tape specimens prepared by combination and repetition of cold work (or cold press) and sintering showed critical current density Jc as high as 5×103 A/cm2 at 77 K with good reproducibility and reliability, although these specimens are sufficiently thick (0.5–1.0 mm). (Generally, Jc at zero field is inversely proportional to thickness.) For these tape specimens (with Cu sheath), sintering and Jc measurement were performed after the Cu sheath was removed. X‐ray analysis showed that most of these tape specimens consist purely of high‐Tc phase (∼107 K). In these specimens, the c axis tends to align well. This c axis alignment as well as compacting effect may be a cause of the enhancement in Jc . On the other hand, the tape specimens cold‐worked and sintered only once (not repeated) showed Jc as small as only 102 A/cm2 with the c axis showing no sign of alignment. A 1330‐filament Bi‐Pb‐Sr‐Ca‐Cu‐O wire with a Ag sheath has been successfully fabricated. This multifilamentary wire shows critical temperature Tc of ∼105 K. A multifilamentary tape specimen fabricated by a combination of cold work and sintering showed Jc of 1.05×103 A/cm2 at 77 K.

This publication has 5 references indexed in Scilit: