The effects of variable oxygen partial pressures during Bi-2223 tape processing

Journal Article · Sat Nov 01 04:00:00 EST 1997 · Journal of Materials Research

DOI:https://doi.org/10.1557/JMR.1997.0398· OSTI ID:573764

Holesinger, T G; Bingert, J F ^[1]; Willis, J O ^[2]; Maroni, V A; Fischer, A K ^[3]; Wu, K T ^[4]

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1. MST-6, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
3. Chemical Science and Technology, Argonne National Laboratory, Argonne, Illinois 60521 (United States)
4. State University of New York/Old Westbury Campus, Old Westbury, New York 11568 (United States)

The effect of changes in the oxygen partial pressure during the heat treatment of Bi-2223 tapes has been investigated. Distinct differences were observed in the phase assemblages, compositions, and critical current densities. Of particular importance in the correlation of transport properties and microstructure was the redistribution of lead in both the secondary phases and the Bi-2223 matrix. The highest J{sub c} values were associated with tapes that contained Ca{sub 2}PbO{sub 4} as part of the phase assemblage coupled with lower concentrations of lead in the superconducting phase. The high J{sub c} of 30.4kA/cm{sup 2} was obtained in tapes processed at 820{degree}C where the oxygen partial pressure was increased from 10{percent} O{sub 2}/Ar to 20{percent} O{sub 2}/Ar after 25 h of each 50-h sinter cycle. Samples processed only in 10{percent} O{sub 2}/Ar at 820{degree}C did not contain Ca{sub 2}PbO{sub 4}, had slightly higher concentrations of lead in the superconducting phase, and had significantly lower J{sub c} values. {copyright} {ital 1997 Materials Research Society.}

• DOE Contract Number: W-31109-ENG-38; W-7405-ENG-36
• OSTI ID: 573764
• Journal Information: Journal of Materials Research, Journal Name: Journal of Materials Research Journal Issue: 11 Vol. 12; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH OXIDES
CALCIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
HEAT TREATMENTS
HIGH-TC SUPERCONDUCTORS
LEAD OXIDES
MICROSTRUCTURE
PHASE STUDIES
PRESSURE DEPENDENCE
STRONTIUM OXIDES
SUPERCONDUCTING COMPOSITES