Fabrication of (Bi,Pb){sub 2.2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} Ag-sheathed superconducting wires from non-phase-pure powders
- Argonne National Lab., IL (United States). Energy Technology Division
- Univ. of Illinois, Chicago, IL (United States). Dept. of Civil Engineering, Mechanics, and Metallurgy
A two-powder processing scheme for forming the Pb-doped 2223 phase in the Bi-Sr-Ca-Cu-0 system has shown remarkable improvements in phase purity over conventional practice. This process controls the reaction pathway by forming separate intermediate phases (Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2{minus}x}Ca{sub 1+x}Cu{sub 2}O{sub 8} and Sr{sub x}Ca{sub 1{minus}x}CuO{sub 2}) and then combining them to react in situ during the oxide powder-in-tube process. In studying this processing scheme, the effects of two variables were examined. The first variable studied was the Sr/Ca ratio as determined by x in the above formulae (x = 0.0, 0.25, 0.5, 0.75, and 1.0). The second variable was the amount of lead incorporated in the intermediate phase, as determined by the subscript y in the formulae Bi{sub 1.8}Pb{sub y}Sr{sub 2}CaCu{sub 2}O{sub 8}. The most favorable processing parameters were: 8% partial pressure of O{sub 2} atmosphere; 815 C firing temperature; mixtures containing the phases 2212, Ca{sub 2}CuO{sub 3}, and CuO; where all Pb is incorporated into the 2212. Nearly phase pure 2223 ({<=} 2 volume, percent second phase) can be obtained in as few as 50 hours firing time. To date, the maximum critical current density achieved was 4.0 {times} 10{sup 4} A/cm{sup 2} (I{sub c} = 60 A) at 77K and 18.0 {times} 10{sup 4} A/cm{sup 2} (I{sub c} = 270 A) at 4.2K.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 43004
- Report Number(s):
- CONF-9310224-; ISBN 0-87339-271-X; TRN: IM9521%%168
- Resource Relation:
- Conference: Materials Week `93, Pittsburgh, PA (United States), 17-21 Oct 1993; Other Information: PBD: 1994; Related Information: Is Part Of Processing of long lengths of superconductors; Balachandran, U. [ed.] [Argonne National Lab., IL (United States)]; Collings, E.W. [ed.] [Battelle Columbus Division, Columbus, OH (United States)]; Goyal, A. [ed.] [Oak Ridge National Lab., TN (United States)]; PB: 371 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Synthesis of (BiPb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} superconductors by the sol-gel process
Thermostability and decomposition of the (Bi,Pb) sub 2 Sr sub 2 Ca sub 2 Cu sub 3 O sub 10 phase in silver-clad tapes