Intergranular fluxons in high-T[sub c] superconductors

Journal Article · Tue Jun 01 04:00:00 EDT 1993 · Journal of Superconductivity; (United States)

DOI:https://doi.org/10.1007/BF00625742· OSTI ID:7112178

Vaccarone, R ^[1]

---

1. I.N.F.N., Genoa (Italy)

The granular high-T[sub c] superconductors can carry very low transport current, in comparison to that found in the bulk of the material. Magnetization and critical current measurements at very low field indicate that this low transport current behaves as expected from a critical state model. The presence of weak links between the grains in granular aggregates is firmly established, together with the Josephson character of such links. The existence of some kind of magnetic particles, and of a mechanism of pinning for them, is required to explain the critical state regime. In this paper we examine the flux structures which can be present in the granular systems, which can be described by an array of SQUIDs, and we show their similarities to fluxons in a continuous medium and to fluxons in uniform Josephson junctions. A simple model, based on a two-dimensional network of pointlike Josephson junctions, is adequate to demonstrate the existance of the IF (intergranular fluxon). Its characteristics depend on a single parameter, which gives the coupling strength between grains. The discreteness of the system is the cause of an intrinsic pinning of the intergranular fluxons. 13 refs., 12 figs.

• OSTI ID: 7112178
• Journal Information: Journal of Superconductivity; (United States), Journal Name: Journal of Superconductivity; (United States) Vol. 6:3; ISSN 0896-1107; ISSN JOUSEH
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
665412 -- Superconducting Devices-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRITICAL CURRENT
CURRENTS
ELECTRIC CURRENTS
ELECTRONIC EQUIPMENT
EQUIPMENT
FLUXMETERS
GRANULAR MATERIALS
HIGH-TC SUPERCONDUCTORS
JOSEPHSON EFFECT
JOSEPHSON JUNCTIONS
JUNCTIONS
MAGNETIC FLUX
MAGNETIC PROPERTIES
MAGNETIZATION
MATERIALS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
PHYSICAL PROPERTIES
SQUID DEVICES
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTORS