Accession Number : AD0644182

Title :   ULTRASONIC AND THERMAL EFFECTS IN SUPERCONDUCTORS.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF PHYSICS

Personal Author(s) : Kagiwada,Reynold S.

Report Date : DEC 1966

Pagination or Media Count : 148

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)

Descriptors :   (*SUPERCONDUCTORS, ELECTRICAL PROPERTIES), ULTRASONIC RADIATION, NIOBIUM, VANADIUM, TANTALUM, PHONONS, TEMPERATURE, ANISOTROPY, ENERGY, ATTENUATION, PROPAGATION

Subject Categories : Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE