Raman Study Of The Interface Between Hot-Pressed Silica Parts

This paper presents a Raman spectroscopy study of silica glasses prepared by hot-pressing of gels. Of particular interest is the structure at the interfaces formed during hot-pressing of small parts to obtain large pieces, such as silica tubes for optical fibre preforms. A specific feature of the interface that distinguishes this layer from the bulk is is fractal structure. The parameters of the fractal units, including their maximum dimensions in real space, are determined by the pre-hot pressing mechanical processing.