Title :
Microstructural and magneto-optical characterization of high J/sub c/ BSCCO-2223/Ag tapes
Author :
Jiang, J. ; Shields, T.C. ; Abell, J.S. ; Polyanskii, A. ; Feldmann, D.M. ; Larbalestier, D.C.
Author_Institution :
Sch. of Metall. & Mater., Birmingham Univ., UK
fDate :
6/1/1999 12:00:00 AM
Abstract :
The phase and microstructural evolution, and critical current density of (Bi,Pb)-2223/Ag tapes prepared from a variety of precursor powders have been investigated. Correlations between the reaction kinetics, the microstructure and the critical current density are developed. A mechanism for the BSCCO-2223 phase formation depending on the precursor phase assemblage is presented. Magneto-optical imaging shows that high J/sub c/ samples (J/sub c/ (77 K, 0 T) /spl sim/35 kA/cm/sup 2/) are well connected longitudinally but strongly sub-divided by longitudinal cracks. The performance of BSCCO-2223 tapes should be further improved by controlling the liquid phase to better heal the cracks.
Keywords :
bismuth compounds; calcium compounds; critical current density (superconductivity); crystal microstructure; high-temperature superconductors; magneto-optical effects; silver; strontium compounds; superconducting tapes; 0 T; 2223 phase formation; 77 K; Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O-Ag; critical current density; longitudinal cracks; magneto-optical imaging; microstructure; reaction kinetics; superconducting tapes; Critical current density; Magnetic materials; Microstructure; Optical imaging; Powders; Superconducting films; Superconductivity; Wavelength measurement; X-ray diffraction; X-ray scattering;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
