Evidence for a Josephson tunnel current in all {ital in situ} c-YBa{sub 2}Cu{sub 3}O{sub 7}/Pb junctions

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.R3398· OSTI ID:450406

Lesueur, J; Aprili, M; Goulon, A; Horton, T J; Dumoulin, L ^[1]

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1. C.S.N.S.M., CNRS-IN2P3 Batiment 108 Universite Paris-Sud, 91405 Orsay (France)

All {ital in situ} YBu{sub 2}Cu{sub 3}O{sub 7}/Pb and YBa{sub 2}Cu{sub 3}O{sub 7}/Ag/Pb planar tunnel junctions have been successfully made on c-axis-oriented YBa{sub 2}Cu{sub 3}O{sub 7} thin films grown by a coevaporation technique, which show very-low-leakage I-V characteristics. The junctions are hysteretic and display a Josephson current I{sub c} below 7.2 K (lead T{sub c}). The only modification introduced by Ag is a substantial lowering of the normal-state resistance R{sub n}, but the I{sub c}R{sub n} product remains roughly constant. The magnetic-field modulation of I{sub c} shows that the current distribution is rather homogeneous over the whole junction area (0.5 mm{sup 2}), and follows the expected behavior for a short junction on a thin film (thickness {lt}{lambda}{sub ab}). The Josephson coupling between a conventional superconductor and the high-T{sub c} compound YBa{sub 2}Cu{sub 3}O{sub 7} along its c axis indicates that an s component is present in the superconducting order parameter of this material. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 450406
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 6 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BARIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
DEPOSITION
ELECTRICAL PROPERTIES
HIGH-TC SUPERCONDUCTORS
JOSEPHSON EFFECT
JOSEPHSON JUNCTIONS
LEAD
ORDER PARAMETERS
PROXIMITY EFFECT
SILVER
SUPERCONDUCTING FILMS
THIN FILMS
TUNNEL EFFECT
YTTRIUM OXIDES