Superconducting transport properties of grain boundaries in YBa sub 2 Cu sub 3 O sub 7 bicrystals

Journal Article · Thu Mar 01 00:00:00 EST 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.4038· OSTI ID:6977555

Dimos, D; Chaudhari, P ^[1]; Mannhart, J ^[2]

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1. IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (USA)
2. IBM Research Division, Zuerich Research Laboratory, CH-8803 Rueschlikon, Switzerland (CH)

Previous work on the superconducting transport properties of individual grain boundaries in thin-film bicrystals of YBa{sub 2}Cu{sub 3}O{sub 7} has been extended to provide a more comprehensive picture of their weak-link characteristics. Grain boundaries with three different geometries have been studied; the transport properties of all three types of boundaries are essentially identical, which implies that the poor superconducting coupling between grains is a result of the intrinsic structural disorder at the boundary. The grain-boundary critical current densities in bicrystal films prepared by evaporation and postannealing and by laser ablation are also in good agreement; this result demonstrates that the transport properties are insensitive to preparation technique and, thus, are not dominated by the diffusion of substrate impurities into the boundary region. High grain-boundary resistivities and low {ital I}{sub {ital c}R{ital n}} products imply that the boundaries act as strong barriers to current flow with locally depressed order parameters. Strong magnetic hysteresis, associated with trapped intragranular flux, is observed; this hysteretic behavior is also responsible for an increase in the grain boundary {ital J}{sub {ital c}} for {ital H}{sub {ital a}{ital p}{ital p}}{gt}300--500 Oe.

• OSTI ID: 6977555
• Journal Information: Physical Review, B: Condensed Matter; (USA), Vol. 41:7; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
GRAIN BOUNDARIES
COPPER OXIDES
YTTRIUM OXIDES
ANISOTROPY
CRITICAL CURRENT
CRYSTAL STRUCTURE
MAGNETIC FIELDS
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CURRENTS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties