Accession Number : ADA192907

Title :   Superconducting Electronic Film Structures.

Descriptive Note : Final rept. 1 Jan-31 Dec 87,

Corporate Author : WESTINGHOUSE RESEARCH AND DEVELOPMENT CENTER PITTSBURGH PA

Personal Author(s) : Braginski, A I ; Gavaler, J R ; Talvacchio, J

PDF Url : ADA192907

Report Date : 24 Jan 1988

Pagination or Media Count : 26

Abstract : Bulk samples of the new oxide superconductors were prepared and some of their properties measured. Thin films of yttrium-barium-copper-oxide, completely superconducting below 85K, were prepared by both sputtering and evaporation. The sputtered films on (100) and (110) strontium-titanium-oxide substrates were epitaxial. A correlation between oxygen content in as-deposited films and the formation of non-superconducting surface layers was established. The thickness of these layers was greatly reduced by sputtering in argon and oxygen gas mixtures. The presence of fluorine in the evaporated films was also found effective in minimizing the barium segregation which produces such layers. Zero resistance gold contact layers were obtained on Y-Ba-Cu-O-sputtered films which were processed entirely in situ. Tunneling data using a low-temperature tunneling microscope were obtained on both evaporated and sputtered Y-Ba-Cu-O films. A new surface characterization capability based on the analysis of (Low Energy Electron Diffraction) or (Reflection High Energy Electron Diffraction) diffraction spot intensity was developed.

Descriptors :   *SUPERCONDUCTORS, *CRYSTAL STRUCTURE, *FILMS, ARGON, DIFFRACTION, ELECTRON DIFFRACTION, ELECTRONIC EQUIPMENT, EVAPORATION, FLUORINE, GASES, INTENSITY, LOW ENERGY, LOW TEMPERATURE, MICROSCOPES, MIXTURES, OXIDES, OXYGEN, REDUCTION, SAMPLING, SEGREGATION(METALLURGY), SPUTTERING, STRUCTURAL PROPERTIES, THICKNESS, THICK FILMS, EPITAXIAL GROWTH, COPPER COMPOUNDS, YTTRIUM COMPOUNDS, TUNNELING(ELECTRONICS)

Subject Categories : Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE