Large-area YBCO films for microwave applications

Conference · Fri Mar 01 04:00:00 EST 1991 · IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States)

OSTI ID:5720845

Talvacchio, J; Forrester, M G; Gavaler, J R; Braggins, T T ^[1]

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1. Westinghouse Science and Technology Center, Pittsburgh, PA (US)

This paper presents techniques for the in- situ deposition of epitaxial YBCO films on two-inch diameter wafers of LaAlO{sub 3}(001) or {alpha}-Al{sub 2}O{sub 3} (1{bar 1}02) with a Sr-doped La{sub 2}CuO{sub 4}(001) (LSCO) buffer layer. The inductively-measured transition temperature varied within the values of 91.1 {plus minus} 0.5K across the surface of the LaAlO{sub 3} wafer, and 90.7 {plus minus} 0.4K across the buffered sapphire wafer. The epitaxial LSCO buffer layer acted not only as a barrier to diffusion of Al into the YBCO films, but improved the YBCO (005) x-ray rocking curve widths from 4 for films grown on bare sapphire to 1.2 for films on the LSCO-buffered sapphire. The typical buffer-layer thickness was 40 nm although layers as thin as 4 nm appeared to be equally effective. The transport critical current density was greater than 10{sup 6} A/cm{sup 2} at 77 K for films on buffered sapphire. At 8.8 GHz and 4.2K, the rf surface resistance was lower than that of gold, indicating that the films on sapphire will be useful in large-area UHF applications.

• OSTI ID: 5720845
• Report Number(s): CONF-900944--
• Conference Information: Journal Name: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States) Journal Volume: 27:2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
665412 -- Superconducting Devices-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CORUNDUM
CRITICAL CURRENT
CURRENT DENSITY
CURRENTS
DOPED MATERIALS
ELECTRIC CURRENTS
ELECTRONIC EQUIPMENT
ELEMENTS
EPITAXY
EQUIPMENT
FILMS
GOLD
IN-SITU PROCESSING
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MATERIALS
METALS
MICROWAVE EQUIPMENT
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PROCESSING
RARE EARTH COMPOUNDS
SAPPHIRE
STRONTIUM
SUPERCONDUCTING FILMS
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TRANSITION TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES