Abstract
The structure of glasses is characterized by the existence of density and composition fluctuations on the nanometre scale. We present three examples of the use of small-angle X-ray scattering to get information about these density fluctuations. The thermal history and OH content were observed to have a huge influence. The static compressibility decreases when the OH content or fictive temperature increase. We showed that temperature scanning small-angle X-ray scattering can provide an accurate description of the position, width and shape of the glass transition.