Accession Number : AD0716474

Title :   Megahertz and Gigahertz Ultrasonic Attenuation Studies in Metals.

Descriptive Note : Final technical rept.,

Corporate Author : WAYNE STATE UNIV DETROIT MICH DEPT OF PHYSICS

Personal Author(s) : Bohm,Henry V. ; Thomas,Robert L. ; Tepley,Norman

Report Date : 30 SEP 1970

Pagination or Media Count : 9

Abstract : The use of standard ultrasonic techniques at frequencies from 10MHz to 10GHz is reported together with the development and application of the new technique of direct electromagnetic sound generation to probe the electron transport properties of metals in both the normal and superconducting states. A state-dependent electron mean free path has been deduced for the superconductor mercury, and a limiting behavior at high ultrasonic frequencies is found for pure mercury which is found to be anomalous (non-BSC-like). Sophisticated data acquisition and processing methods have been applied for a detailed ultrasonic quantum oscillation study of th Spin Density Wave electronic ground state of chromium. The earlier ultrasonic work of Wallace and Bohm has been extended, results compared with existing de Haas van Alphen measurements, and evidence reported for magnetic breakdown effects. Measurements of a variety of magnetoacoustic effects at Gigabertz frequencies were made on bismuth and gallium. The possibility of a Spin Density Wave ground state of potassium has been investigated carefully, both by the deHaas - van Alphen effect and by electromagnetic sound generation. (Author)

Descriptors :   (*BAND THEORY OF SOLIDS, METALS), (*ULTRASONIC RADIATION, METALS), (*SUPERCONDUCTORS, ULTRASONIC RADIATION), BISMUTH, CHROMIUM, GALLIUM, MERCURY, POTASSIUM, ANTIFERROMAGNETISM, GROUND STATE, SINGLE CRYSTALS, ATTENUATION

Subject Categories : Acoustics
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE