J. Phys. Colloques
Volume 42, Numéro C6, Décembre 1981International Conference on Phonon Physics
|Page(s)||C6-849 - C6-851|
J. Phys. Colloques 42 (1981) C6-849-C6-851
MODE CONVERSION COEFFICIENTS OF ACOUSTIC WAVES AT A CRYSTAL-VACUUM INTERFACEJ. Throwe et W.E. Bron
Indiana University, Bloomington, IN 47405, U.S.A.
Recent work by Taborek1 et al has shown that the reflection of acoustic phonons from a sapphire-vacuum interface is divided between a specular component which is predicted by elastic theory and a diffuse component. Knowledge of the magnitude and direction of the specular component is useful in the design of experiments to study the frequency dependence of the reflection process. We have generated mode conversion coefficients for infinite plane waves traveling initially in the x direction and incident at various angles on perfect surfaces in quartz, sapphire, and ZnO. For waves propagating in the xy-plane, ZnO behaves as an isotropic solid whereas quartz, because of its anisotropy, exhibits new transverse reflections beyond the critical angle.