Small-angle neutron scattering on silica glasses containing titania

Abstract

Small-angle scattering (SAS) of neutrons is applied to the investigation of the microinhomogeneous structure of glasses. The alumina–silica titania-containing systems are taken as the subject of the investigation. The negative sign of the Ti nuclear scattering amplitude sharply extends the sensitivity to fluctuations of the atomic density. The phase-segregation kinetics was studied in the temperature region 750–950°C. A comparison of neutron SAS data with the data from X-ray phase analysis and neutron diffraction has shown that the process of segregation into two amorphous phases is accompanied by the simultaneous ordering of the titania-rich phase up to the appearance of crystallites. The `glass-in-glass' state corresponds only to the initial stages of the decomposition.