Phonon Scattering in a Sol-Gel Glass

Abstract

Oxide glasses can be produced by a sol-gel process involving the heat treatment of gels made by hydrolysis and gelation of metal alkoxides. The glasses thus obtained are virtually indistinguishable from those produced by conventional melt techniques [1]. Prior to final heating, however, the gels differ noticeably from the conventional glasses. For example, the gels are porous and, consequently, have densities and sound velocities that are reduced relative to the final product. A comparison of the low-temperature thermal properties of a sol-gel product (prior to compaction) and those of the final product is of interest because of the potential to provide information about the gel-to-glass conversion, as well as the nature of glasses in general.