Distribution of the transport critical current in Ag-(Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/ reinforced tape-form conductors

Author

Glowacki, B.A. ; Lo, W. ; Yuan, J. ; Jackiewicz, J. ; Liang, W.Y.

Author_Institution

Cambridge Univ., UK

Volume

3

Issue

1

fYear

1993

fDate

3/1/1993 12:00:00 AM

Firstpage

953

Lastpage

956

Abstract

The spatial distribution of the transport critical current, I/sub c/, in the reinforced-tape-form, silver-clad (Bi,Pb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/ conductor manufactured by cold multistep rolling has been established by the in-situ measurements as a function of the thickness of the ceramic core. The measurements show that current is almost uniformly distributed through the whole cross-section of the core in the wire, almost independently of the initial I/sub c/ value of the tape. The effect of densification, texturing, and surface diffusion on the formation of the intergrain connectivity along the a-b plane of the core, at the silver-ceramic interface, and in the core has been investigated and is discussed in detail. The I/sub c/ anisotropy measurements and a study of magnetically aligned and randomly oriented samples lead to a functional relationship between the crystallographic orientation, morphology and connectivity of the grains in the tape. The variation of the hole concentration near the grain boundary region of the 2223 phase has been investigated by transmission electron energy loss spectroscopy.<>

Keywords

bismuth compounds; calcium compounds; composite superconductors; critical current density (superconductivity); crystal orientation; electron energy loss spectra; grain boundaries; high-temperature superconductors; lead compounds; silver; strontium compounds; superconductive tunnelling; surface diffusion; Ag-Bi/sub 2-x/Pb/sub x/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/; ceramic core; crystallographic orientation; densification; grain boundary; high temperature superconductivity; intergrain connectivity; morphology; multistep rolling; reinforced-tape; spatial distribution; surface diffusion; texturing; transmission electron energy loss; transport critical current; Ceramics; Conductors; Critical current; Current measurement; Magnetic cores; Manufacturing; Strontium; Surface morphology; Thickness measurement; Wire;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.233854

Filename

233854