Phonon Imaging of Highly Dislocated LiF

Abstract

It has been found that high-frequency acoustic phonons with certain polarizations can propagate ballistically through a highly deformed LiF crystal. With use of the method of phonon imaging, a large anisotropy has been observed in the phonon-dislocation interaction—the crystal acts as a phonon polarizer. The data are consistent with the fluttering dislocation model. Phonon-focusing and anisotropic-scattering processes profoundly affect the transport of heat through a dislocated crystal.