Accession Number : AD0617102

Title :   ELASTIC CONSTANTS OF AND WAVE PROPAGATION IN ANTIMONY AND BISMUTH.

Descriptive Note : Technical rept.,

Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH N J

Personal Author(s) : Epstein ,Seymour ; deBretteville,Alex P. , Jr

Report Date : MAR 1965

Pagination or Media Count : 23

Abstract : Ultrasonic wave velocities for 14 different modes were obtained on two differently oriented single crystal antimony cubes from the time between successive unrectified radio frequency pulse echoes. This redundant set of data was fitted by a least squares technique to Voigt theory to yield the six room temperature adiabatic elastic stiffness constants. In units of 10 to the 10th power dynes/sq cm, c sub 11 = 99.4(1), c sub 33 = 44.5(9), c sub 44 = 39.5(5), c sub 66 = 34.2(3), c sub 13 = 26.4(4), c sub 14 = +21.6(4), the positive sign for c sub 14 following from our choice of positive Cartesian axes. When similarly treated, Eckstein, Lawson, and Reneker's bismuth data yield in these same units c sub 11 = 63.22, c sub 33 = 38.11, c sub 44 = 11.30, c sub 66 = 19.40, c sub 13 = 24.40 =.09, c sub 14 = +7.20. Also included are a visual method of fixing the laboratory coordinate system in antimony by means of an imperfect cleavage plane, a calculation of the pure mode directions in the mirror plane, a simple formula for choosing the nonextraneous value of c sub 13 for trigonal crystals having six independent elastic constants without resorting to lattice stability criteria, and a calculation of the deviation of elastic wave particle displacement and energy flux directions from the propagation direction. For waves propagating in the (0,1,1) and (0,1,1) directions, the particle displacement deviations for antimony and bismuth do not exceed 15 degrees and 13 degrees respectively, and corresponding energy flux deviations up to 45 degrees and 27 degrees are obtained. (Author)

Descriptors :   (*ANTIMONY, ULTRASONIC RADIATION), (*BISMUTH, ULTRASONIC RADIATION), (*ULTRASONIC RADIATION, METAL CRYSTALS), SINGLE CRYSTALS, ELASTIC PROPERTIES, REFRACTION, PHONONS, CRYSTAL STRUCTURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE