Preparation and characterization of superconducting phases in the Bi(Pb)-Sr-Ca-Cu-O system

Journal Article · Sun Oct 15 00:00:00 EDT 1989 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.344056· OSTI ID:5419939

Sarkar, A K; Maartense, I ^[1]; Peterson, T L ^[2]; Kumar, B ^[3]

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1. University of Dayton Research Institute, Dayton, Ohio 45469-0001 (US)
2. Wright Research and Development Center, Materials Laboratory (WRDC/MLPO), Wright-Patterson Air Force Base, Ohio 45433-6533
3. University of Dayton Research Institute, Dayton, Ohio 45469-0001

The superconductive properties in the Bi(Pb)-Sr-Ca-Cu-O system with nominal composition of Bi{sub 2{minus}{ital x}}Pb{sub {ital x}}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub {ital y}} ({ital x}=0, 0.2, 0.4, and 0.6) and annealed at 860 {degree}C for 240 h were studied using dc resistivity and ac susceptibility measurements. For {ital x}=0.2 and 0.4, the bulk zero resistivity temperatures were found to be {similar to}103 K. For {ital x}=0 and 0.6, these temperatures were found to be {similar to}73--75 K. The ac susceptibility data show enrichment of the volume fraction of the high-{ital T}{sub {ital c}} phase in compositions with {ital x}=0.2 and 0.4. {ital T}{sub {ital c}} of this phase is constant at 107 K for all values of {ital x}. The enhancement of the bulk zero resistivity temperature for {ital x}=0.2 and 0.4 is due to the improved intergranular coupling of the high-{ital T}{sub {ital c}} phase, although the resulting weak-link behavior reflects a low current carrying capacity in these materials. The presence of the low-{ital T}{sub {ital c}} phase ({similar to}65 K) is still visible in the susceptibility data. For {ital x}=0.6, the intergranular coupling of the high-{ital T}{sub {ital c}} phase is almost destroyed; however, the coupling of the low-{ital T}{sub {ital c}} phase is better than when {ital x}=0. Powder x-ray diffraction and scanning electron microscopy data show the formation of large grains of the calcium plumbate, Ca{sub 2}PbO{sub 4} phase with increasing Pb up to {ital x}=0.6. The large grains of the Ca{sub 2} PbO{sub 4} phase may incorporate other impurity phases within it when {ital x}=0.6, cleaning up the remaining grain boundaries, thereby improving the intergranular coupling within this material. Energy dispersive x-ray analysis indicates that some Pb is incorporated into the structure of both superconducting phases.

• OSTI ID: 5419939
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 66:8; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
GRANULAR MATERIALS
LEAD COMPOUNDS
LEAD OXIDES
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MATERIALS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POWDERS
SCANNING ELECTRON MICROSCOPY
SCATTERING
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION