Influence of a glass matrix on acoustic phonons confined in microcrystals

The influence of a glass matrix on the spheroidal and torsional vibrational modes of microcrystals embedded into the matrix is analyzed. The low-frequency Raman scattering data are used to show that the influence of the matrix on the frequencies of the acoustic phonons confined in the microcrystals is significant even if Lame's constants {λ} and {μ} and mass densities of a microcrystal and a matrix are quite different from each other. It was found that surface vibrations arise as microcrystals are embedded in a matrix. These vibrations are caused by the restoring force which limits the free rotation of microcrystals. Most likely, just these vibrations take part in the low-frequency Raman scattering described in a number of papers. {} 1996 The American Physical Society.