Surface layers on superconducting Y-Ba-Cu-O films studied with x-ray photoelectron spectroscopy

Journal Article · Mon Oct 16 04:00:00 EDT 1989 · Applied Physics Letters; (USA)

DOI:https://doi.org/10.1063/1.102314· OSTI ID:5490527

Chang, C C; Hegde, M S; Wu, X D; Dutta, B; Inam, A; Venkatesan, T; Wilkens, B J; Wachtman, Jr, J B ^[1]

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1. Bellcore, Red Bank, New Jersey 07701 (US)

The chemical compositions of surface and bulk regions of pulsed laser deposited YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} films on SrTiO{sub 3}(001) substrates were examined. From the relative intensities of the surface and bulk components of the Ba 3{ital d} and Ba 4{ital d} spectra taken at different take-off angles and different escape depths (using Al {ital K}{alpha} (1486.6 eV) and Mg {ital K}{alpha} (1253.6 eV) excitations), we have concluded that there is a nonsuperconducting surface layer of 1 nm thickness with a composition of BaCuO{sub 2}. This layer contains oxygen with a photoelectron binding energy of 531 eV, and Cu{sup 2+} ions. A superconducting film which was only 8 nm thick also had a layer of 1 nm thickness. By detecting the substrate Ti signal through this film, and ruling out a high density of pinholes, we provide evidence that the x-ray photoelectron spectroscopy data contain information from the superconducting phase. A polycrystalline pellet scraped in vacuum had a similar surface layer, which was only 0.4 nm thick.

• OSTI ID: 5490527
• Journal Information: Applied Physics Letters; (USA), Journal Name: Applied Physics Letters; (USA) Vol. 55:16; ISSN APPLA; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
CHEMICAL COMPOSITION
COPPER COMPOUNDS
COPPER OXIDES
CRITICAL CURRENT
CURRENT DENSITY
CURRENTS
DATA
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
EXPERIMENTAL DATA
FILMS
INFORMATION
LAYERS
LOW TEMPERATURE
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
SPECTROSCOPY
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTING FILMS
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
THICKNESS
THIN FILMS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES