POLYMORPHIC ETHYL-ALCOHOL AS A MODEL SYSTEM FOR THE QUANTITATIVE STUDY OF GLASSY BEHAVIOR

We have performed neutron diffraction experiments as well as neutron t ime-of-flight (TOF) and low-temperature specific heat (C-p) measuremen ts, on both hydrogenated and deuterated ethanol as functions of temper ature. Ethanol appears to be unique in its ability to form a rotator-p hase crystal and an orientational glass in the same temperature range where the amorphous phase can be produced. We find that these two orie ntationally disordered crystal phases have structures and dynamics whi ch are very similar to those of the amorphous phase at the same temper ature. These are therefore glassy systems which, due to the presence o f an underlying lattice and a stoichiometry identical to the amorphous phase, are ideal for quantitative study.