Superconducting Electronic Film Structures
Abstract
Modification in Y-Ba-Cu-O growth procedures were instituted to eliminate non-superconducting near-surface layers observed in films. These include much higher ramp rates to the 850 C crystallization temperature of the as-deposited amorphous films and the use of an entirely in-situ processing. Films have now been grown which are superconducting up to the surface. Other Y- Ba-Cu-O films have been sputtered which are crystalline (tetragonal) as- deposited. These films. Gold layers deposited at room temperature on recent films were found to have contact resistance less than the limit of the apparatus sensitivity. Evidence for crystallinity and epitaxy was found in 10 nm YBCO films deposited at 650 C from the vapor phase. Measurements on superconducting resonator cavities have begun using epitaxial films on SrTiO3 substrates. Thin epitaxial MgO layers were grown on sapphire to eventually provide a better substrate for this application. Y-Ba-Cu-O/MgO/Nb tunnel junctions were fabricated. Non-continuous barrier layer produced superconducting shorts in the junctions. This result, however, provided the non-ambiguous evidence that the new growth procedures had produced films which were superconducting up to the surface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 28, 1988
- Accession Number
- ADA200534
Entities
People
- A. I. Braginski
- J. R. Gavaler
- J. Talvacchio