LOW-TEMPERATURE THERMAL-PROPERTIES OF MOLECULAR GLASSES AND CRYSTALS

We have developed two instrumental arrangements for the measurement of low-temperature specific heat and thermal conductivity of molecular g lasses and crystals, which are liquid at ambient temperature. We prese nt measurements carried out with ethanol (CH3CH2OH). Ethanol is an org anic low-molecular-weight substance, which exhibits polymorphism. Ther e are three different phases at low temperature: a stable monoclinic c rystal, a conventional structural grass, and an orientational glass pr oduced by supercooling a plastic crystalline state. Fully-deuterated e thanol (CD3CD2OD) has also been studied. The specific heat C-p(T) and the thermal conductivity kappa(T) of several crystalline and glassy st ates of ethanol have been measured in the temperature range from aroun d 2 K up to 30 K. All structural and orientational glassy states show the so-called ''anomalous'' thermal properties of common inorganic gla sses.