Adiabatic calorimeter as an ultra-low frequency spectrometer: interplay between phase and glass transitions in solids

Abstract

Principle and procedure of an adiabatic calorimeter used for an ultra-low frequency spectrometer was described in detail. Structural relaxation in glass-forming liquids and vapor-quenched non-crystalline solids were compared in terms of the Kohlrausch–Williams–Watts’ (KWW) empirical equation and the fictive temperature. Kinetic parameters for the structural recovery were analyzed by using the Adam–Gibbs entropy theory. Anomalous behavior of configurational entropy observed for some molecular systems below T g was discussed. Freezing-in phenomena that occurred in some orientationally disordered crystals (ODC) and anisotropic liquids were described, stressing a wide occurrence of glass transitions in condensed states of matter. Interplay between the phase and glass transitions was discussed in relation to useful dopants which accelerate some molecular motions that had failed to maintain equilibrium at low-temperatures.