Vortex-persistent current interaction, Meissner effect, and diamagnetic shielding in a ring of YBa sub 2 Cu sub 3 O sub 7

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.6466· OSTI ID:6837035

Mohamed, M A; Jung, J; Franck, J P ^[1]

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1. Department of Physics, University of Alberta, Edmonton, Canada, T6G2J1 (CA)

The vortex-persistent current interaction, Meissner effect, and diamagnetic shielding in a ring of YBa{sub 2}Cu{sub 3}O{sub 7} have been studied by the measurement of the magnetic-field distributions across the sample and their time dependence at 77 K over an applied magnetic-field range 0--1000 G. The measurements were performed both for zero-field-cooling (ZFC) and field-cooling (FC) cases. Drilling a hole in a disk results in a time-dependent decay of the diamagnetic shielding and a time-dependent increase of the Meissner field being observed. The dependence of a trapped magnetic field on an applied magnetic field shows a maximum at an applied field of 150--200 G for the ZFC case and of 60--80 G for the FC case. For the ZFC case the magnetic field is trapped at applied magnetic fields as low as 10 G. The trapped flux (intergranular vortices) and macroscopic persistent current circulating around the ring contribute to the trapped field. The logarithmic decay rate of the trapped field is a linear function of an initial trapped field for the disk of YBa{sub 2}Cu{sub 3}O{sub 7}. The decay rate of the trapped field for the ring of YBa{sub 2}Cu{sub 3}O{sub 7} was measured both at its center and its edge. The results revealed a jump in the decay rate at trapped fields in the range 5--10 G for the ZFC case. These results are interpreted as being due to the Josephson vortex-persistent current interaction in the ring. The Josephson vortex motion in the ring is the combination of flux-creep- and flux-flow-like processes.

• OSTI ID: 6837035
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:10; ISSN PRBMD; ISSN 0163-1829
• 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
COPPER COMPOUNDS
COPPER OXIDES
CURRENTS
DIAMAGNETISM
ELECTRIC CURRENTS
INTERACTIONS
JOSEPHSON EFFECT
LOW TEMPERATURE
MAGNETIC FIELDS
MAGNETISM
MEISSNER-OCHSENFELD EFFECT
OXIDES
OXYGEN COMPOUNDS
RINGS
SPACE DEPENDENCE
TIME DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES