Accession Number : AD0808053

Title :   ACOUSTIC WAVES AND DISLOCATION MOTIONS.

Descriptive Note : Technical rept.,

Corporate Author : COLUMBIA UNIV NEW YORK INST FOR THE STUDY OF FATIGUE AND RELIABILITY

Personal Author(s) : Mason, Warren P.

Report Date : OCT 1966

Pagination or Media Count : 60

Abstract : High frequency attenuation measurements along the <110> direction have been made for lead, copper and aluminum single crystals for frequency ranges from 30 MHz to 150 MHz and temperatures from 50 K to 300 K. In some cases all three modes, the longitudinal and the two shear modes have been measured. It is found in all cases that the attenuation can be decomposed into a square law frequency curve and a dislocation curve of a standard form. Square law curves are accounted for by the thermoelastic effect and the phonon and electron viscosity effects. When the third order moduli are known a quantitative agreement is found. When these are not known, the attenuation allows an evaluation of the missing non-linearity constant. The separated dislocation losses allow an evaluation of the drag coefficient and the measured values are consistent with a phonon scattering drag, a phonon viscosity drag and an electron drag term. (Author)

Descriptors :   (*MECHANICAL WAVES, MOTION), (*ACOUSTICS, MECHANICAL WAVES), DISLOCATIONS, SEPARATION, TEMPERATURE, ATTENUATION, DAMPING, SINGLE CRYSTALS, LEAD(METAL), COPPER, ALUMINUM, HIGH FREQUENCY, VERY HIGH FREQUENCY, PHONONS, ELECTRONS, DRAG, SCATTERING.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE