Superconducting electronic-film structures. Annual report, 1 January-31 December 1985

Technical Report · Tue Feb 04 04:00:00 EST 1986

OSTI ID:6415735

Bragninski, A I; Gavaler, J R

Results from niobium/tin and niobium/aluminum diffusion-couple experiments show that oxygen or oxides can have a positive influence on the nucleation and growth of stable as well as metastable A15 phases. Data on the effect of epitaxy and the addition of carbon impurities on the critical temperatures of niobium nitride films deposited at low temperatures show that both are effective in stabilizing the stoichiometric B1 phase. Critical temperatures of 16.4K were obtained in epitaxially grown NbN films deposited on <100C substrates. According to RHEED and X-ray rocking-curve data, high-quality single-crystal films of the technologically important A15 and B1 superconductors, including Nb-Sn, Nb-Ge, and NbN can be reproducibly grown in the new deposition and analytical facility. Low-leakage all-NbN tunnel junctions were developed with ion-beam oxidized Al and M barriers, or rf-sputtered magnsium oxide barriers. The first Nb-Sn based junctions with refractory counterelectrodes were fabricated. XPS, RHEED, and tunneling were 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) junctions proceed at temperatures up to 800 C. 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: 6415735
• Report Number(s): AD-A-179148/2/XAB
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment &amp; Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
BEAMS
BETA-W LATTICES
CARBON
CHALCOGENIDES
CHEMICAL REACTIONS
CRITICAL TEMPERATURE
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DEPOSITION
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
FILMS
GERMANIUM ALLOYS
GRAPHS
IMPURITIES
ION BEAMS
JUNCTIONS
LOW TEMPERATURE
METALS
NIOBIUM ALLOYS
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
NUCLEATION
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
REFRACTORY METAL COMPOUNDS
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
THIN FILMS
TIN
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE