Thin Superconducting Film Characterization by Surface Acoustic Waves.
Abstract
Surface acoustic wave attenuation (SAW) and electrical resistivity on In/InO films has been measured. On one film it was found that both vortex antivortex dipoles associated with a Kosterlitz Thouless transition and excess local resistivity associated with granularity of the film contribute to the energy absorption in the film. On another film, with a high sheet resistivity, a peak in attenuation is observed which may be associated with a metal insulator transition at the local level. A technique for determining average grain size in a granular superconductor has been proposed. Proximity acoustoelectric coupling to a granular A1 superconducting film has been demonstrated. This technique may be used to determine the separation between two surfaces that are less than 1000A apart. Measurement on the Er(1-x)Ho(x)Rh4B4 alloy system have been completed. A theoretical relaxation expression has been derived and is being used to analyze the maxima that have been observed in the attenuation curves. Preliminary measurements of both the attenuation and velocity of longitudinal waves in a single crystal of URu2Si2 have been performed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 13, 1986
- Accession Number
- ADA174904
Entities
People
- Moises Levy
Organizations
- University of Wisconsin–Milwaukee