Tunneling in cuprate and bismuthate superconductors

Conference · Tue Oct 01 00:00:00 EDT 1991

OSTI ID:6108781

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

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1. Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Physics
2. Argonne National Lab., IL (United States)

Tunneling measurements using a point-contact technique are reported for the following high temperature superconducting oxides: Ba{sub 1-x}K{sub x}BiO{sub 3}(BKBO), Nd{sub 2-x}Ce{sub 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 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}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 {Angstrom} thick.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE; National Science Foundation (NSF); USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6108781
• Report Number(s): ANL/CP-74820; CONF-9109102-4; ON: DE92004135; CNN: DMR-8809854
• Resource Relation: Conference: 5. annual conference on superconductivity and applications, Buffalo, NY (United States), 24-26 Sep 1991
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH OXIDES
TUNNEL EFFECT
CUPRATES
HIGH-TC SUPERCONDUCTORS
BARIUM OXIDES
CALCIUM OXIDES
CERIUM OXIDES
ENERGY GAP
NEODYMIUM OXIDES
POTASSIUM OXIDES
PROXIMITY EFFECT
SPECTROSCOPY
STRONTIUM OXIDES
THALLIUM OXIDES
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CERIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
NEODYMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
RARE EARTH COMPOUNDS
STRONTIUM COMPOUNDS
SUPERCONDUCTORS
THALLIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360207* - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)
665411 - Basic Superconductivity Studies- (1992-)