Connecting structure and dynamics in glass forming materials by photon correlation spectroscopy

We report photon correlation spectroscopy measurements of the alpha-relaxation in a series of glass forming liquids of widely varying fragility and demonstrate a correlation between the nonergodic level of the liquid and its fragility. This correlation, when combined with a previous correlation established between fragility and the stretching exponent that characterizes the nonexponentiality of the alpha-relaxation, implies that the alpha-relaxation should, in general, conform to scaling that is described by just two parameters: the nonergodic level and the glass transition temperature.