Correlation of current-voltage characteristics of step-edge YBa{sub 2}Cu{sub 3}O{sub 7} Josephson junctions with the step angle

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:64681

Herrmann, K; Siegel, M; Kunkel, G; Thust, A; Kabius, B; Jia, C L; Schubert, J; Braginski, A I ^[1]

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1. Forschungszentrum Juelich (Germany)

The authors report on a systematic study of the transport characteristics of YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) step-edge Josephson junctions as a function of the step angle. The microstructure of a YBCO film depends very critically on the step angle a in a SrTiO{sub 3} or LaAlO{sub 3} substrate. Briefly, on shallow steps (0 < {alpha} < 44{degree}) the film grows epitaxially across the step. On 45{degree} steps multiple domains separated by 90{degree} grain boundaries occur in the flank film on the step. On steep steps (46{degree} < {alpha} < 85{degree}) two grain boundaries occur on the step. In this paper it is shown that the 1-5 curves of the step-edge junction reflect the microstructure of the YBCO film on the step. The I-V curves on shallow steps are of flux-flow type. On 45{degree} steps there are several Josephson junctions with different critical currents, while on steep steps two critical currents are found in the 1-5 curve. Summarizing all data, they conclude that the grain boundaries formed on steep steps are responsible for the Josephson behavior of the junctions.

• OSTI ID: 64681
• Report Number(s): CONF-940142--; ISBN 0-8194-1455-7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
BARIUM OXIDES
COPPER OXIDES
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
FABRICATION
HIGH-TC SUPERCONDUCTORS
JOSEPHSON EFFECT
JOSEPHSON JUNCTIONS
MICROSTRUCTURE
SUPERCONDUCTING FILMS
YTTRIUM OXIDES