| Autor: |
León-Gutierrez, E., Garcia, G., Lopeandía, A. F., Fraxedas, J., Clavaguera-Mora, M. T., Rodríguez-Viejo, J. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 11/14/2008, Vol. 129 Issue 18, p181101, 4p, 2 Diagrams, 3 Graphs |
| Abstrakt: |
In this work, we describe the design and first experimental results of a new setup that combines evaporation of liquids in ultrahigh vacuum conditions with in situ high sensitivity thermal characterization of thin films. Organic compounds are deposited from the vapor directly onto a liquid nitrogen cooled substrate, permitting the preparation and characterization of glassy films. The substrate consists of a microfabricated, membrane-based nanocalorimeter that permits in situ measurements of heat capacity under ultrafast heating rates (up to 105 K/s) in the temperature range of 100–300 K. Three glass forming liquids—toluene, methanol, and acetic acid—are characterized. The spikes in heat capacity related to the glass-transition temperature, the fictive temperature and, in some cases, the onset temperature of crystallization are determined for several heating rates. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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