Microwave surface resistance of epitaxial YBa sub 2 Cu sub 3 O sub 7 thin films on sapphire

Journal Article · Mon Jul 23 04:00:00 EDT 1990 · Applied Physics Letters; (USA)

DOI:https://doi.org/10.1063/1.103651· OSTI ID:6728842

Char, K; Newman, N; Garrison, S M; Barton, R W ^[1]; Taber, R C; Laderman, S S; Jacowitz, R D ^[2]

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1. Conductus, Inc., Sunnyvale, California 94086 (USA)
2. Hewlett-Packard Company, Palo Alto, California 94304 (USA)

Microwave surface resistance data were measured on pairs of YBa{sub 2}Cu{sub 3}O{sub 7} thin films on Al{sub 2}O{sub 3} {l brace}1102{r brace} substrates by a parallel plate resonator technique. The surface resistance {ital R}{sub {ital s}} at 10 GHz was 65 {mu}{Omega} at 10 K and 850 {mu}{Omega} at 77 K. These epitaxial YBa{sub 2}Cu{sub 3}O{sub 7} films were grown on 500-A-thick buffer layers of SrTiO{sub 3}. X-ray diffraction data showed that the YBCO thin films with the SrTiO{sub 3} buffer layers have better in-plane epitaxy than those without such buffer layers. Critical current density of 2{times}10{sup 6} A/cm{sup 2} at 74 K was measured by the ac mutual inductance response of the films. The improved microwave surface resistance and the higher critical current density are believed to be the results of better in-plane epitaxy.

• OSTI ID: 6728842
• Journal Information: Applied Physics Letters; (USA), Journal Name: Applied Physics Letters; (USA) Vol. 57:4; ISSN APPLA; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CORUNDUM
CRITICAL CURRENT
CURRENT DENSITY
CURRENTS
ELECTRIC CURRENTS
ELECTRIC IMPEDANCE
FILMS
HIGH-TC SUPERCONDUCTORS
IMPEDANCE
LOW TEMPERATURE
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SAPPHIRE
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES