Regensburg 2013 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 5: Glasses and Glass Transition I (joint session DY/CPP)
CPP 5.2: Talk
Monday, March 11, 2013, 15:30–15:45, H34
In-situ investigation of vapor-deposited thin films of toluene and ethylbenzene by AC chip-nanocalorimetry — •Mathias Ahrenberg1, Katie R. Whitaker2, Yeong-Zen Chua1, Heiko Huth1, Mark D. Ediger2, and Christoph Schick1 — 1Institut für Physik, Universität Rostock, Wismarsche Str. 43-45, 18051 Rostock, Germany — 2Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Physical vapor deposition can be used to produce thin films with particular material properties. For example extraordinarily stable glasses can be obtained from organic molecules like toluene and ethylbenzene. We have investigated properties like packing efficiency and kinetic stability depending on substrate temperature and deposition rate by in-situ AC chip-nanocalorimetry. We have varied the substrate temperature covering the range from temperatures proven to yield high enthalpy glasses up to temperatures proven to yield low enthalpy glasses. This way the complete evolution of the mentioned stable glass properties is observed. Moreover AC calorimetry offers the possibility for isothermal measurements which enables to follow the transformation of the stable glass to the super-cooled liquid. Transformation experiments give suggestion of the transformation mechanism and its temperature dependence. The data are in agreement with a growth front for the transformation of the stable glass into the supercooled liquid.