Observation of large tunneling-conductance variations in direct mapping of the energy gap of single-crystal Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8 minus x

Journal Article · Tue Sep 01 04:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.5692· OSTI ID:7279648

Chang, A; Rong, Z Y; Ivanchenko, Y M; Lu, F; Wolf, E L ^[1]

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1. Department of Physics, Polytechnic University, Brooklyn, New York 11201 (United States)

The tunneling conductance {ital G}({ital V},{ital x},{ital y}) is mapped with 5 A resolution on cleaved {ital a}-{ital b} planes of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8{minus}{ital x}} crystals ({ital T}{sub {ital c}}=90 K) using scanning (vacuum) tunneling spectroscopy at 4.2 K. A strong, spatially varying {ital G}({ital V},{ital x},{ital y}), evidently arising from a superconducting gap {Delta}{sub {ital c}}, is observed on the {ital a}-{ital b} plane. A more highly peaked {ital G}({ital V}) with reduced peak spacing is seen near ({similar to}50 A) specific sites, and over broader areas. It is suggested that the striking variations in {ital G}({ital V},{ital x},{ital y}) probably indicate local variations in BiO-layer metallicity, revealing an internal superconducting proximity effect between BiO and CuO{sub 2} layers.

• DOE Contract Number: FG02-87ER45301
• OSTI ID: 7279648
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:9; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360607* -- Other Materials-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY GAP
HIGH-TC SUPERCONDUCTORS
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PROXIMITY EFFECT
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
TUNNEL EFFECT