Spatial variation of the current in grain boundary Josephson junctions

Journal Article · Wed Mar 01 04:00:00 EST 2000 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.372201· OSTI ID:20215427

Carmody, M ^[1]; Moeckly, B H ^[2]; Merkle, K L ^[3]; Marks, L D ^[1]

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1. Materials Science and Engineering Department, Northwestern University, Evanston, Illinois 60208 (United States)
2. Conductus, Inc., 969 West Maude Avenue, Sunnyvale, California 94086 (United States)
3. Materials Science Division and Science Technology Center for Superconductivity, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

The spatial variation of the current across the boundary in several YBa{sub 2}Cu{sub 3}O{sub 7-x} grain boundary Josephson junctions was determined using direct methods. A phase retrieval algorithm was used to calculate the positional critical current density J(x) from critical current versus applied magnetic field, I{sub c}(B), measurements. The current distributions were highly nonuniform along the length of the junctions. These measurements are consistent with existing filamentary grain boundary models, low temperature scanning microscopy studies, and laser scanning microscopy studies of high T{sub c} grain boundaries. The very large scatter in the critical currents reported in the literature for grain boundaries of the same macroscopic geometry appear to be due to the underlying variations in local critical currents. (c) 2000 American Institute of Physics.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• OSTI ID: 20215427
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 5 Vol. 87; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
GRAIN BOUNDARIES
JOSEPHSON JUNCTIONS
MAGNETIC FIELDS
THEORETICAL DATA
YTTRIUM OXIDES