Title :
The influence of precursor preparation on the superconducting properties of Bi(2223) tapes
Author :
Polasek, A. ; Xia, S.K. ; Lisboa, M.B. ; Sens, M.A. ; Serra, E.T. ; Rizzo, F. ; Borges, H.
Author_Institution :
CEPEL, Rio de Janeiro, Brazil
fDate :
6/1/1999 12:00:00 AM
Abstract :
The effect of preparation of precursor powders on the formation of Bi-2223 phase and critical current density (J/sub c/) of OPIT tapes, was studied. The precursors were prepared by "one-powder" and "two-powder" methods. The results indicate that a sufficiently large fraction of second phases in the precursors is crucial for obtaining pure 2223 phase and high J/sub c/ values. It is also revealed that the (Sr,Ca)/sub 2/CuO/sub 3/ second phase promotes a faster phase transformation of 2212 to 2223 than other second phases in the precursors. Tapes prepared with "one-powder" precursor achieved J/sub c/ of 25.5 kA/cm/sup 2/, while the J/sub c/ for the tapes made from "two-powder" precursors had values of about 12 kA/cm/sup 2/.
Keywords :
bismuth compounds; calcium compounds; critical current density (superconductivity); high-temperature superconductors; materials preparation; powder technology; strontium compounds; superconducting tapes; (Sr,Ca)/sub 2/CuO/sub 3/ second phase; Bi(2212) to Bi(2223) phase transformation; Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 10/; OPIT; critical current density; one-powder method; oxide powder in tube method; precursor powder preparation; second phase fraction; superconducting properties; tapes; two-powder method; Calcination; Critical current density; Current density; Laboratories; Large-scale systems; Manufacturing; Microstructure; Powders; Superconducting films; Transistors;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
