INFLUENCE OF A GLASS MATRIX ON ACOUSTIC PHONONS CONFINED IN MICROCRYSTALS

The influence of a glass matrix on the spheroidal and torsional vibrat ional modes of microcrystals embedded into the matrix is analyzed. The low-frequency Raman scattering data are used to show that the influen ce of the matrix on the frequencies of the acoustic phonons confined i n the microcrystals is significant even if Lame's constants lambda and mu and mass densities of a microcrystal and a matrix are quite differ ent from each other. It was found that surface vibrations arise as mic rocrystals are embedded in a matrix. These vibrations are caused by th e restoring force which limits the free rotation of microcrystals. Mos t likely, just these vibrations take part in the low-frequency Raman s cattering described in a number of papers.