Regensburg 2007 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 3: Liquid and amorphous materials I

MM 3.4: Vortrag

Montag, 26. März 2007, 11:00–11:15, H4

Thermophysical properties of Si, Ge and Si-Ge melts under microgravity — •Suresh Mavila Chathoth, Bernd Damaschke, and Konrad Samwer — I. Physikalisches Institut, Universitaet Göttingen, 37077 Göttingen, Germany

The liquid Si and Ge are highly reactive materials. Especially the liquid Si is known to reactive with almost all materials. To have an accurate values of thermophysical properties of these melts container less processing is required. The container less processing can be realized by electromagnetic or electrostatic levitation. These ground based levitation techniques have demerits of gravity driven convection and accuracy of the data depend on convection currents. The thermophysical properties of Si, Ge and Si-Ge alloy melts have been investigated in the TEMPUS facility on board of Zero-G plane during the parabolic flights. Unlike metallic alloys [1] which can melt in a magnetic field, Si, Ge and Si-Ge are semiconductors in their sold state a laser pre-heating was necessary to melt these samples. The melted droplets were video taped and from the images the thermal expansion and surface tension of the samples were evaluated. Absence of gravity driven convection a separation of the influence of gravity induced convection become possible by comparing the data with ground based experiments. The work was supported by BMBF/DLR under grant No. 50WM0541.

[1] B. Damaschke, D. Oelgeschlaeger, J. Ehrich, E. Dietzsch, and K. Samwer, Rev. Sci. Instrum. 69, 2110 (1998).