ULTRASONIC AND THERMAL EFFECTS IN SUPERCONDUCTORS.
Abstract
Some of the properties of three transition metals, niobium, vanadium, and tantalum, were investigated using the ultrasonic technique. The normal attenuation in niobium possessed a typical electron-phonon behavior with a temperature dependence of T to the -3.2 power. In the superconducting state, attenuation was measured in both the absence of a magnetic field and at various values of the external magnetic field. From the ratio of superconducting to normal conducting attenuation, the zero-degree energy gaps of niobium, vanadium, and tantalum were determined. For niobium, an energy gap of 2 delta (0) = 3.64 plus or minus 0.05 kT sub c was found for the 100 direction of propagation, and an energy gap of 3.70 plus or minus 0.06 kT sub c for the 111 direction. These measurements indicate an anisotropy of the energy gap. The zero-degree energy gap for vanadium was 2 delta (0) = 3.40 plus or minus 0.07 kT sub c in the 110 direction, and 3.10 plus or minus 0.07 kT sub c for tantalum in the 100 direction. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1966
- Accession Number
- AD0644182
Entities
People
- Reynold S. Kagiwada
Organizations
- University of California, Los Angeles