Accession Number:

ADA179148

Title:

Superconducting Electronic Film Structures.

Descriptive Note:

Annual rept. 1 Jan-31 Dec 85,

Corporate Author:

WESTINGHOUSE RESEARCH AND DEVELOPMENT CENTER PITTSBURGH PA

Personal Author(s):

Report Date:

1986-02-04

Pagination or Media Count:

20.0

Abstract:

Results from NiobiumTin and NbAluminum 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 uiobium 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-Germanium, and NbN can be reproducibly grown in the new deposition and analytical facility. Low-leakage all-NbN tunnel junctions have been developed with ion-beam oxidized AL and Magresium barriers, or rf-sputtered Magnsium Oxide 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 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.

Subject Categories:

  • Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE