The effect of processing on the microstructure of Ag-sheathed Bi-2223 wires

Conference · Mon Nov 01 04:00:00 EST 1993

OSTI ID:10110430

Miller, D J; Hu, J G; Kostic, P; Balachandran, U ^[1]; Haldar, P ^[2]

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1. Argonne National Lab., IL (United States)
2. Intermagnetics General Corp., Guilderland, NY (United States)

Studies using TEM and SEM, focused on effect of final heat treatment conditions on microstructure of (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x}(Bi-2223)wires and corresponding variations in critical currents (I{sub c}). It is found that variations in I{sub c} for segments cut from various points along length of a wire can be correlated with variations in volume fraction and nature of second phases. Similar variations are observed between wires processed under different final annealing conditions. A common feature found in all of the wire segments with lower I{sub c} values was presence of the Pb{sub 3}Sr{sub 2}Ca{sub 2}CuO{sub x} phase (Pb-3221). Microchemical analysis suggests that formation of this phase leads to variations in composition of Bi-2223 grains. As a result, the wires which exhibit the Pb-3221 phase consist of an assemblage of grains with a range of transition temperatures based on composition. Thus, in these segments, the current carrying capacity of individual grains at 77K varies from very good to poor, and a significant reduction in the overall I{sub c} of the segment is observed.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10110430
• Report Number(s): ANL/MSD/CP--81484; CONF-931009--15; ON: DE94004627
• Country of Publication: United States
• Language: English

Related Subjects

665412
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH OXIDES
CALCIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
HIGH-TC SUPERCONDUCTORS
LEAD OXIDES
MICROSTRUCTURE
STRONTIUM OXIDES
SUPERCONDUCTING DEVICES
SUPERCONDUCTING WIRES