Specific heat of ethanol at low temperatures
- 作者：Virginia Rodriguez-Mora ; Miguel A. Ramos
- 关键词：Glass-transition ; Calorimetry ; Thermodynamics ; Water in glass
- 刊名：Journal of Non-Crystalline Solids
- 出版年：2008
- 期刊代码：50_00223093
- 类别：ms
- 出版时间：15 January 2008
- 卷：354
- 期：2-9
- 页码：263-268
- 文件大小：391 K
摘要
We present here new specific heat measurements at low temperatures (2–20 K) of the different phases of ethanol, characterized by the same calorimetric set-up at higher temperatures. We have extended and improved earlier measurements by implementing higher-accuracy calorimetric methods at low temperatures (using two complementary versions of the thermal relaxation method), as well as at higher temperatures (using a quasi-adiabatic, continuous method). The quantitatively very similar low temperature properties and glass-transition features of both structural glass and orientationally-disordered crystal of ethanol provide clear evidence that the lack of long-range crystalline order typical of amorphous solids is an unimportant factor regarding the universal properties of glasses. We have also employed these new measuring methods to study the possible effect of water impurities on the specific heat of the different solid phases of ethanol, and to study possible variations in the specific heat between different found phases of the monoclinic crystal of ethanol.