Fabrication, processing and properties of Tl-1223 conductors

Author

Goyal, A. ; Paranthaman, M. ; Qing He ; List, F.A. ; Specht, E.D. ; Christen, D.K. ; Kroeger, D.M. ; Tkacyzk, J.E. ; Haldar, P.

Author_Institution

Oak Ridge Nat. Lab., TN, USA

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

1405

Lastpage

1408

Abstract

Fabrication of Tl-1223 conductors in two geometries is reported. Powder-in-tube (PIT) tapes were fabricated using aerosol generated precursor powders mixed with Tl/sub 2/O/sub 3/. Effect of processing variables such as temperature, time and uniaxial pressure were studied. Under optimum processing conditions the tapes have sharp transitions (widths /spl sim/1 K) and zero-field J/sub c//spl sim/0.9/spl times/10/sup 4/ A/cm/sup 2/ at 77 K, However the tapes lack any detectable grain orientation texture and are severely weak-linked. On the other hand, thick films (3-30 /spl mu/m) of Tl-1223 on Ag made using a variety of precursor deposition techniques followed by thallination in a two-zone flow reactor, show significantly reduced weak-link behavior and high zero-field J/sub c/´s (>10/sup 4/ A/cm/sup 2/). It is found that these films are c-axis aligned (rocking curve FWHM/spl sim/3-11/spl deg/) and also possess varying degrees of local in-plane texture. Microstructural development in these thick films is found to be similar to that observed previously for films on polycrystalline YSZ. Such thick films present a working model of a practical Tl-1223 conductor.<>

Keywords

Josephson effect; barium compounds; calcium compounds; crystal microstructure; grain size; high-temperature superconductors; powders; silver; sintering; superconducting thin films; superconducting transition temperature; texture; thallium compounds; 3 to 30 mum; 77 K; Tl-1223 conductors; Tl/sub 0.8/Ba/sub 2/Ca/sub 2/Cu/sub 3/Ag/sub 0.37/O; c-axis aligned; fabrication; grain orientation texture; high temperature superconductors; local in-plane texture; microstructural development; powder-in-tube tapes; processing; properties; sharp transitions; weak-links; Aerosols; Conducting materials; Conductors; Fabrication; High temperature superconductors; Inductors; Powders; Silver; Superconducting films; Thick films;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.402827

Filename

402827