Investigation of Phase Formation in Glasses using Different Small-Angle X-ray Scattering Techniques. Rainer Brückner, University of Missouri, Columbia, Department of Physics; Ulrich Lembke, Rainer Kranold, Universität Rostock, Fachbereich Physik

In contrast to the conventional small-angle X-ray scattering technique (SAXS) contrast variation permits investigation of the spatial arrangement of distinct elements in the phase separating system owing to the fact that the scattering amplitude of an atom is decreased for X-ray energies near the absorption edge of the concerning element. This anomalous dispersion is the basis for the method of Anomalous Small-Angle X-ray Scattering (ASAXS) of synchrotron radiation.

For in situ SAXS studies of phase formation in transmission geometry a high temperature sample chamber was developed which fulfills the requirements of a small thermal capacity of the heating elements and the sample holder as well. This sample chamber allows SAXS-measurements up to 1300 K with heating rates between 5 - 50 K/s, cooling rates between 20 - 1 K/s and with a stability of the temperature of +/- 1 K over many hours, respectively.

The use of small-angle X-ray scattering with varying the contrast and some results of the in situ small-angle X-ray experiments will be illustrated in the discussion of SAXS-studies of different types of glasses.