Collective dynamical aspect related to vitrification in connection with structural characterization

Structural characterization has been made for the same disordered material in 3 different thermodynamic states: liquid, supercooled and glassy. It concerns the aqueous electrolyte LiCl, 6H2O. Using isotopic substitution, we can analyse the pair distribution functions and precise the modifications induced by the glass transition and the melting in the short, medium and long range order. Particularly interesting is the medium range order (between four and five A), which appears more similar in the supercooled and glassy state than in the liquid state. On the basis of this structural analysis we will discuss the collective dynamical motion and the relaxational behavior. Because the investigated materials are aqueous solutions, comparison will be made with the H-bond characteristics.