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TT: Tiefe Temperaturen

TT 7: Superconductivity & Solids At Low Temperature - Poster Session

TT 7.71: Poster

Montag, 27. März 2006, 14:00–17:45, P1

Thermal Conductivity of Solid Ethanol in the Three Polymorphous Phases — •Alexey Yushchenko, Alexander Krivchikov, Korolyuk Oksana, Gorodilov Boris, and Manzhelii Vadim — B.Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine

Solid ethyl alcohol can be obtained in three metastable long-living phases - position glass, an orientationally-disordered (static disorder) crystal (orientational glass) and a crystal with dynamic orientational disorder. The orientationally - ordered monoclinic - system crystal is the only thermodynamically equilibrium solid phase of the alcohol.
In this work the temperature dependence of the thermal conductivity of solid ethanol was measured in all solid phases under equilibrium vapor pressure at 2-159 K by the steady-state potentiometric method. The glass phase was obtained by cooling the container with liquid nitrogen at an extremely high rate (over 50 K/min). The orientationally - disordered bcc crystal phase was formed on hardening the slowly overcooled liquid at T = 125 K. An orientationally - ordered crystal evolved in the process of rapid crystallization provoked by heating the bcc phase to over 116 K. The recrystallized sample was then annealed for several days at a temperature close to the melting point.
Obtained data have been analyzed in the borders of the soft potential model.