Solid state Spectroscopy of Disordered Solids

At present, the group works on several fundamental research projects in the areas of oxide-, fluoride, and chalcogenide glasses. Although many of our systems possess interesting electrical and optical properties (ionic conductivity, IR transparency) our goal is not primarily to develop new functional materials for specific purposes. Rather, we address the question of how the structural organization and local dynamics of glasses can be controlled by compositional, preparation, and processing parameters and how they influence physical properties. For glass synthesis, both traditional melt-cooling and sol-gel chemistry approaches are being used. For structure elucidation we apply the full inventory of modern solid state NMR techniques, including the results of our own technique-oriented NMR research for developing comprehensive descriptions of structural and dynamic properties of our systems. Additional information about the solid state structure is provided by Raman and Mössbauer spectroscopic studies. Complementary to our solid state NMR approach we are characterizing the chemical equilibria present in glass forming melts via high-temperature liquid state NMR. In the same vein, the molecular mechanisms of sol-gel pathways towards glasses are being studied by appropriate spectroscopic methods applied in the solution and gel states.