Surface Acoustic Wave Investigation of Superconducting Films,
Abstract
The ultrasonic attenuation coefficient of 2 GHz surface waves in a 300 A aluminum film has been measured in the normal and superconducting state. A zero temperature energy gap of (kB(TC) is found for the Al film. Microwave electromagnetic attenuation measurements in the film indicate critical fluctation effects near Tc. However, the evidence for the contribution of fluctuation effects to the ultrasonic attenuation data of this short mean free path al film is not conclusive. The mean free path determined from the electron phonon interaction term obtained from the ultrasonic measurement appears to be at least an order of magnitude larger than the mean free path obtained from a measurement of the electrical conductivity of this thin granular aluminum film. This large difference is believed to indicate that the mean free path determined ultrasonically is for the Al metal while the one determined electrically is for the Al-Al2O3 matrix structure. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1976
- Accession Number
- ADA037597
Entities
People
- David A. Robinson
- Harry Salvo Jr.
- Kazumi Maki
- Masashi Tachiki
- Moises Levy
Organizations
- University of Wisconsin–Madison