Granular Josephson and quantum interference effects in HTC ceramic superconductors

Journal Article · Mon May 01 00:00:00 EDT 1989 · IBM Journal of Research and Development; (USA)

DOI:https://doi.org/10.1147/rd.333.0262· OSTI ID:5521316

Gough, C E ^[1]

---

1. Univ. of Birmingham Superconductivity, Research Group, Birmingham, B15 2TT (GB)

Josephson effects in high-T/sub c/ superconductors are briefly reviewed, with specific reference to granular ceramic materials and SQUID device applications. It is suggested that the inductance associated with intergranular current loops may play an important role, even in determining the bulk superconductivity properties, as in weak-link superconducting rings. Evidence for quantum interference effects within intergranular current loops is presented. In ultra-low fields, the observed temperature dependence of thermally activated flux creep cannot be described by a simple granular superconductor model of equally spaced pinning centers but would seem to imply a hierarchy of pinning sites of variable strength. The development of liquid-nitrogen-cooled rf and dc SQUIDS is described, and the noise levels currently achieved are presented.

• OSTI ID: 5521316
• Journal Information: IBM Journal of Research and Development; (USA), Vol. 33:3; ISSN 0018-8646
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CERAMICS
JOSEPHSON EFFECT
SQUID DEVICES
COOLING
DESIGN
DISLOCATION PINNING
NITROGEN
NOISE
RF SYSTEMS
SUPERCONDUCTIVITY
SUPERCONDUCTORS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
FLUXMETERS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
NONMETALS
PHYSICAL PROPERTIES
SUPERCONDUCTING DEVICES
420201* - Engineering- Cryogenic Equipment & Devices
360204 - Ceramics
Cermets
& Refractories- Physical Properties
656100 - Condensed Matter Physics- Superconductivity