Tunneling in cuprate and bismuthate superconductors

Conference · Wed Apr 01 04:00:00 EST 1992 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:5000353

Zasadzinski, J F; Huang, Q; Tralshawala, N ^[1]; Gray, K E ^[2]

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1. Illinois Institute of Technology, Chicago, IL 60616 (United States)
2. Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

Tunneling measurements using a point-contact technique are reported for the following high temperature superconducting oxides: Ba{sub 1{minus}{ital x}}K{sub {ital x}}BiO{sub 3}(BKBO), Nd{sub 2{minus}{ital x}}Ce{sub {ital x}}CuO{sub 4} (NCCO), Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 7} (BSCCO) and Tl{sub 2}Ba{sub 2}CaCu{sub 2}O{sub {ital x} }(TBCCO). For the bismuthate, BKBO, ideal, S-I-N tunneling characteristics are observed using a Au tip. The normalized conductance is fitted to a BCS density of states and thermal smearing only proving there is no fundamental limitation in BKBO for device applications. For the cuprates, the normalized conductance displays BCS-like characteristics, but with a broadening larger than from thermal smearing. Energy gap values are presented for each material. For BKBO and NCCO the Eliashberg functions, {alpha}{sup 2}{ital F}({omega}), obtained from the tunneling are shown to be in good agreement with neutron scattering results. Proximity effect tunneling studies are reported for Au/BSCCO bilayers and show that the energy gap of BSCCO can be observed through Au layers up to 600 A thick.

• OSTI ID: 5000353
• Report Number(s): CONF-9109102--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Journal Volume: 251:1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
POTASSIUM OXIDES
PROXIMITY EFFECT
RARE EARTH COMPOUNDS
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTORS
THALLIUM COMPOUNDS
THALLIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TUNNEL EFFECT