Microstructure of epitaxial YBa sub 2 Cu sub 3 O sub 7 minus x thin films

Journal Article · Mon May 21 04:00:00 EDT 1990 · Applied Physics Letters; (USA)

DOI:https://doi.org/10.1063/1.103237· OSTI ID:6819528

Nieh, C W; Anthony, L ^[1]; Josefowicz, J Y; Krajenbrink, F G ^[2]

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1. Keck Laboratory of Engineering, California Institute of Technology, Pasadena, CA (USA)
2. Hughes Research Laboratories, Malibu, CA (USA)

We have investigated the microstructure of epitaxial YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} thin films on SrTiO{sub 3}(100), LaGaO{sub 3}(100), and LaAlO{sub 3} (100) with particular emphasis on how the final microstructure is developed. Cross-sectional transmission electron microscopy as well as plan-view transmission electron microscopy combined with sputter depth profiling were used to study the change in microstructure with the increase in film thickness. For a thin film or near the substrate/film interface of a thick film, the YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} film is composed primarily of grains oriented with {ital c} axis normal to the substrate surface and a small volume fraction of grains with {ital c} axis parallel to the substrate surface. As the film grows thicker, the {ital c}-axis parallel grains increase in size and grow over the top of the {ital c}-axis normal grains. The volume fraction of {ital c}-axis parallel grains increases rapidly as the film thickness increases and eventually the entire film surface is covered by {ital c}-axis parallel grains. However, the number density of the {ital c}-axis parallel grains remains constant throughout the whole film thickness. A growth model is proposed to explain the observed microstructure. Based on this model, a computer simulation is carried out. The simulated microstructure agrees well with the experimental result.

• OSTI ID: 6819528
• Journal Information: Applied Physics Letters; (USA), Journal Name: Applied Physics Letters; (USA) Vol. 56:21; ISSN APPLA; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL GROWTH
CRYSTAL MODELS
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FILMS
MATHEMATICAL MODELS
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SUBSTRATES
SUPERCONDUCTIVITY
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES