Lead-rich phases in partially processed Ag/Bi-2223 composite conductors

Conference · Thu Feb 01 04:00:00 EST 1996

OSTI ID:226421

Luo, J S; Merchant, N; Maroni, V A

The occurrence, composition, and melting behavior of lead-rich phases detected during the thermal processing of Ag/Bi-2223 composite conductors have been investigated by a combination of transmission electron microscopy (TEM), energy dispersive analysis (EDS), x-ray diffraction, differential thermal analysis, and Raman spectroscopy. A (Bi,Pb)-Sr-Ca-Cu-O composition with {open_quotes}4112{close_quotes} metal atom stoichiometry and Pb{approx_equal}Bi was detected during TEM/EDS examinations of partially processed/quenched Ag/Bi-2223 composites. An as-synthesized oxide mix with this stoichiometry was found to melt at a temperature <700{degrees}C. The lead-rich {open_quotes}3221{close_quotes} phase was found to have a wide range of compositional stability in terms of Pb/Bi ratio and Bi + Pb stoichiometry. Evidence was seen for the co-existence of this phase with (Ca,Sr){sub 2}PbO{sub 4} in partially processed Ag/Bi-2223 composites that were cooled slowly through the 800 to 600{degrees}C range.

• Research Organization: Argonne National Lab., IL (United States); American Superconductor Corp., Westborough, MA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 226421
• Report Number(s): ANL/CMT/CP--89594; CONF-960202--23; ON: DE96009126
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
BISMUTH OXIDES
CALCIUM OXIDES
COMPOSITE MATERIALS
COPPER OXIDES
DIFFERENTIAL THERMAL ANALYSIS
LEAD OXIDES
MELTING
PHASE STUDIES
PHASE TRANSFORMATIONS
PROCESSING
RAMAN SPECTRA
SILVER
STABILITY
STOICHIOMETRY
STRONTIUM OXIDES
SUPERCONDUCTORS
TIME DEPENDENCE
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION