Potential energy, relaxation, vibrational dynamics and the boson peak, of hyperquenched glasses

Laboratory and simulation studies were performed, making it possible to obtain quantitative information on the energy landscape for glass-forming liquids. Focus was on the idea of suddenly extracting the thermal energy, so that the system obtained for subsequent study has the structure, and hence potential energy, of a liquid at a much higher temperature than the normal glass temperature. Results show that, when the temperature is raised at constant pressure, the total density of states changes in a manner that can be well represented by a two-Gaussian excitation across the centroid, leaving a third and major Gaussian component unchanging. The low frequency Gaussian component has a constant peak frequency of 18 cm^-1 and is identified with the Boson peak.