Properties of YBa sub 2 Cu sub 3 Ag sub x O sub 7 minus. delta. composite superconductors

Journal Article · Fri Dec 15 04:00:00 EST 1989 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.343619· OSTI ID:7021330

Ganapathi, L; Kumar, A; Narayan, J ^[1]

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1. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7916 (US)

Superconducting properties and microstructures of the YBa{sub 2}Cu{sub 3}Ag{sub {ital x}}O{sub 7{minus}{delta}} composites have been studied as a function of silver content, 0{lt}{ital x}{lt}6, using a variety of techniques. The superconducting transition temperature {ital T}{sub {ital c}} of these composites was found to be the same, {similar to}90 K, for the above range of composites. For values of {ital x}{gt}3, small quantities of 211 phase were detected along the grain boundaries. Alloy formation between Ag and Cu is proposed to take place which makes the residual composition poor in copper, resulting in the formation of nonsuperconducting 211 phase. The silver is observed in the form of precipitates at very low concentrations of silver, indicating that silver does not substitute for copper in YBa{sub 2}Cu{sub 3}O{sub 7}. Lattice parameters of the composites were found to be invariant throughout the above composition range. The addition of Ag{sub 2}O in the starting composition seems to stabilize the stoichiometric YBa{sub 2}Cu{sub 3}O{sub 7} by way of decomposition to Ag and O. As a result, the incorporation of oxygen and recovery of superconducting properties is enhanced in the silver composites.

• OSTI ID: 7021330
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 66:12; 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
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COMPOSITE MATERIALS
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
GRAIN BOUNDARIES
LATTICE PARAMETERS
MATERIALS
MICROSCOPY
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
QUANTITY RATIO
SCANNING ELECTRON MICROSCOPY
SCATTERING
SILVER COMPOUNDS
SILVER OXIDES
STOICHIOMETRY
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM OXIDES