Superconducting electronic-film structures. Semiannual report, 1 January-30 June 1985

Technical Report · Mon Aug 05 04:00:00 EDT 1985

OSTI ID:5700668

Braginski, A I; Gavaler, J R

Data from Nb/Sn and Nb/Al diffusion-couple experiments provided supporting evidence for a proposed hypothesis that superconducting A15 compounds are formed via an oxygen-catalyzed reaction. Both epitaxy, and the addition of an impurity (carbon) were successful in increasing the critical temperatures of NbN deposited at low temperature. Critical temperatures of over 16K were obtained in epitaxially grown NbN films sputtered on substrates held at less than 100 C. RHEED and x-ray rocking curve data show that the new UHV deposition and analytical facility has the capability for epitaxially growing high-quality single crystals of the technologically important A15 and B1 superconductors. Low-leakage all-NbN tunnel junctions have been developed with ion-beam oxidized A1 and Mg barriers, or rf-sputtered MgO barriers. The first Nb-Sn based junctions with refractory counterelectrodes were fabricated. XPS, RHEED, and tunneling have been used to characterize: 1) the structure of epitaxial films, 2) the role of ion-beam oxidation in the preparation of tunnel barriers that can be used with refractory counterelectrodes, and 3) anisotropic surface oxide growth on single-crystal films. Nb single-crystal films were prepared which have three times lower rf surface losses compared to polycrystalline Nb.

• Research Organization: Westinghouse Electric Corp., Pittsburgh, PA (USA). Research and Development Center
• OSTI ID: 5700668
• Report Number(s): AD-A-166183/4/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
420201 -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
ANISOTROPY
BEAMS
BETA-W LATTICES
CARBON
COHERENT SCATTERING
CRITICAL TEMPERATURE
CRYSTAL GROWTH
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DEPOSITION
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON DIFFRACTION
ELEMENTS
FABRICATION
FILMS
IMPURITIES
ION BEAMS
JUNCTIONS
LOW TEMPERATURE
NIOBIUM ALLOYS
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
PHYSICAL PROPERTIES
PNICTIDES
REFRACTORY METAL COMPOUNDS
SCATTERING
SUPERCONDUCTING FILMS
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY
SURFACES
THERMODYNAMIC PROPERTIES
TIN ALLOYS
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE