Accession Number : AD0475352

Title :   ULTRASONIC ATTENUATION IN SUPERCONDUCTING ZINC.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Goncz, Joseph P.

Report Date : 1965

Pagination or Media Count : 85

Abstract : Measurements of the ultrasonic attenuation of 10 and 30 Mcs/sec longitudinal waves by pulsed-echo techniques were made on a 99.999% pure single crystal of superconducting zinc in the (0001) direction as a function of temperature from 4.2 K to 0.320 K using an open-ended type He-3 cryostat. The attenuation was found to be frequency dependent and decreased less sharply near the superconducting transition temperature than predicted by the Bardeen-Cooper Schrieffer (BCS) theory. Attenuation due to electron-phonon interactions only was found by subtracting from experimental points the value of residual attenuation gotten by extrapolation of the data to T = 0 K. Using the BCS theory the zero degree superconducting energy gap was determined. (Author)

Descriptors :   *ZINC), (*ULTRASONIC RADIATION, ATTENUATION), (*SUPERCONDUCTORS, METAL CRYSTALS, SINGLE CRYSTALS, SUPERCONDUCTIVITY, CRYOGENICS, CRYOSTATS, COMPUTER PROGRAMMING, PULSES, TRANSITION TEMPERATURE.

Subject Categories : Acoustics
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE