High performance YBCO films. Report for 1 August-31 October 1992

Technical Report · Sat Oct 31 00:00:00 EST 1992

OSTI ID:6797188

Denlinger, E J; Fathy, A; Kalokitis, D; Pendrick, V

The objective of this program is to identify suitable low loss, low dielectric constant substrates and develop and optimize deposition processes for high quality YBCO films including the necessary buffer layers. Ultimate goals are large area substrates having double-sided HTS coating with a surface resistance ten times lower than copper at 40 GHz. High quality HTS films on low dielectric constant substrates are expected to find widespread use in advanced millimeter wave components, in extending the power handling capability of microwave and millimeter wave circuitry, and in facilitating high speed computer interconnects. Sample demonstration circuits will be built toward the end of the program. We have successfully deposited a high quality YBCO film on a good low loss and low dielectric constant substrate, magnesium fluoride (e=5). With the use of two buffer layers (magnesium oxide and strontium titanate) between the YBCO and the substrate, transition temperatures of 89 deg K and transition widths of about 0.5 deg K were achieved. The critical current density Jc of 4 x 10 6 A/cm2 at 77K in zero field is among the highest reported for YBCO films. The magnesium fluoride (MgF2) substrate has a tetragonal structure with a dielectric constant of 5.2 in the plane of the substrate and 4.6 perpendicular to the substrate surface. It has a good harness (-575 Knoop) and a linear thermal expansion coefficient that closely matches YBCO and the buffer layers.

• Research Organization: RCA Labs., Princeton, NJ (United States). David Sarnoff Research Center
• OSTI ID: 6797188
• Report Number(s): AD-A-258481/1/XAB; CNN: N00014-91-C-0216; DARPA Order-8100
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HIGH-TC SUPERCONDUCTORS
CURRENT DENSITY
DIELECTRIC PROPERTIES
TRANSITION TEMPERATURE
SUPERCONDUCTING FILMS
DEPOSITION
BARIUM OXIDES
COPPER OXIDES
CRITICAL CURRENT
INTERMETALLIC COMPOUNDS
MAGNESIUM FLUORIDES
MAGNESIUM OXIDES
MICROWAVE EQUIPMENT
PROGRESS REPORT
STRONTIUM TITANATES
THERMAL EXPANSION
YTTRIUM OXIDES
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
CURRENTS
DOCUMENT TYPES
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELECTRONIC EQUIPMENT
EQUIPMENT
EXPANSION
FILMS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
MAGNESIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STRONTIUM COMPOUNDS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TITANATES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360207* - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication