Accession Number:

ADA110979

Title:

Ultrafine-Grained Superconductors.

Descriptive Note:

Annual rept. 1 Jan-31 Dec 81,

Corporate Author:

WESTINGHOUSE RESEARCH AND DEVELOPMENT CENTER PITTSBURGH PA

Report Date:

1982-01-04

Pagination or Media Count:

19.0

Abstract:

Measurements of the effect of strain on the critical current of NbN show that almost no degradation occurs even at the highest strain levels, 0.5, and the highest fields, 22T, that could be applied. Data at 4.2K in pulsed fields of over 30T suggest that the enhanced critical field measured in ultrafine-grained NbN films are due to a dimensional effect. Data on laser annealed Nb-Ge films further elucidated the role of second-phase pinning in enhancing the critical currents in these films. Electron beam annealing did not enhance significantly the critical current density. Pseudobinary V-Si-C alloys with critical temperatures of 17K were prepared by C-implantation of vanadium-rich V-Si films and subsequent annealing. A theory of current distribution near the end of a filamentary conductor and the effect on ac losses was developed. Some features of the anomalous SAW attenuation measured in NbN films were explained using the Kosterlitz-Thouless theory. Author

Subject Categories:

  • Lasers and Masers
  • Fabrication Metallurgy
  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE