Elastic acoustic scattering

R.H. Hackman, The transition matrix for acoustic and elastic wave scattering in prolate spheroidal coordinates, J. Acoust. Soc. Am. 75, 35 (1984)... 

In these pictures, bright contrast comes from scattering of the acoustic waves by elastic homogeneities in the depth of the specimen. The elastic microstructure of botanical sections has also been studied (Kolodziejczyk et al. 1988). 

In addition to acoustical methods, which take advantage of the fact that gas nuclei (i.e., stable microbubbles) are elastic bodies and thus absorb sound energy (ref. 4,5,9,25,26,31,32,50), another class of methods for detecting these gas microbubbles that has been employed repeatedly is based on their optical behavior. Specifically, most of these optical methods involve detection of these long-lived microbubbles in water from the light scattered by them (ref. 5,26,59,60,127). 

This scattering mode occurs only in piezoelectric materials, i.e., in crystals without inversion symmetry, and is caused by the electric field associated with acoustical phonons. Zinc oxide exhibits very high electro-mechanical coupling coefficients P (see later), exceeding that of quartz [42,59], which is one of the mostly used piezoelectric materials. Zook [60] has calculated the piezoelectrically limited mobility on the basis of the elastic and piezoelectric constants as (see also Rode [54]) ... 

The agreement between fee bulk modulus deduced from Brillouin scattering measurements and fee ADX results is very good. The determination of fee elastic moduli by ultrasonics was made by fee measurement of surface acoustic wave velocities on thin films [22], The second ultrasonics experiment was made on sintered powder, by measuring fee longitudinal and transverse sound velocity at ambient and under uniaxial compression. From feat, fee bulk modulus and its pressure derivative were deduced, but this result seems to be quite imprecise. The ultrasonics experiment on thin films gives rise to a very small difference in fee bulk modulus (5%), but fee ADX or Brillouin determination should be utilised for preference. 

Varadan, V. K., "Multiple Scattering of Acoustic, Electromagnetic and Elastic Waves, Acoustic. Electromagnetic and Elastic Wave Scattering-Focus on the T-Matrix Approach. Pergamon Press, New York, 1980, pp. 103-134. 

---