Berlin 2008 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 18: Poster: Towards Molecular Spintronics, Organic Thin Films, Optical Layers, Vibrational Spectroscopy, Tayloring organic interfaces
DS 18.31: Poster
Dienstag, 26. Februar 2008, 14:30–19:30, Poster A
Evaporation, condensation and annealing of forsterite studied by infrared spectroscopy — •Markus Klevenz1, Michael Möller1, Mario Trieloff2, Dominique Lattard2, and Annemarie Pucci1 — 1Kirchhoff-Institut für Physik der Universität Heidelberg, Deutschland — 2Mineralogisches Institut der Universität Heidelberg, Deutschland
Forsterite (Mg2SiO4) is a silicate that plays a crucial role in the formation of planets and, therefore, it is of special interest in astronomy and mineralogy. Its optical phonons determine the infrared (IR) absorption and emission of protoplanetary disks. For a better understanding of the formation of the silicate compounds and the observed IR spectra, the physical and chemical properties of forsterite and later on those of other relevant silicates will be investigated in laboratory studies under well-defined similar conditions (UHV). First, the vapour pressure curves and the composition of the gas phase will be determined. This will be realized by evaporation from a Knudsen cell with defined temperatures and measuring the molecular flow onto a quartz microbalance and the composition by mass spectroscopy. Afterwards the minerals will be deposited on a substrate and characterized in situ by IR spectroscopy to gather information about the condensation process. Subsequently the deposited films will be annealed up to 1200 K to observe the phase transition from amorphous to crystalline in situ by IR spectroscopy for determining characteristic temperatures and times of the crystallization process.