In situ high temperature x-ray diffraction measurements on a (TiO sub 2 ) sub 0.18 (SiO sub 2 ) sub 0.82 xerogel using a curved image-plate

In situ high temperature x-ray diffraction measurements have been performed on a (TiO sub 2 ) sub 0.18 (SiO sub 2 ) sub 0.82 xerogel using a 185 mm radius curved image-plate. The results clearly show that the coordination of Ti in this material changes from predominantly sixfold to predominantly fourfold as the temperature is increased from 25 deg C to 310 deg C. An increase in the average O-O distance associated with this change is also identified. The use of the curved image-plate is shown to be a valuable technique for in situ studies of structural changes associated with thermal treatment of materials.