Regensburg 2010 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 9: Poster: Synthesis of Nanostructured Films by Self-organization, Thermoelectric Thin Films and Nanostructures, High-k and Low-k Dielectrics, Layer Deposition Processes, Layer Growth, Layer Properties, Application of Thin Films, Surface Modification, Hard and Superhard Coatings, Metal Layers
DS 9.46: Poster
Montag, 22. März 2010, 15:00–17:30, Poster D1
3ω measurements of thermal conductivity in oxide thin films — •Stefanie Wiedigen1, Manuel Feuchter2, Christian Jooss1, and Marc Kamlah2 — 1Institute for Materials Physics, University of Göttingen — 2Institute for Materials Research II, KIT
Several novel approaches for high- efficiency thermoelectric devices are based on thin film geometries like multilayer structures or nanosized devices. Thereby, the 3ω method is one of a few measurement techniques which allows a reliable determination of thin film thermal conductivity. However, the application of the 3ω method on complex geometries and material combinations needs an extension of the standard evaluation techniques. In this contribution, we analyze the conditions for high precision measurements based on the 3ω method in experiment and numerical simulations. For the thin film configurations investigated here, the heat conduction problem is solved by the numerical finite element method. Techniques for modeling the problem and evaluating the results are under development to study the impact of parameters as heater geometry, film thickness and frequency on the voltage signal. The simulation results are compared with the measured frequency spectrum of the ac voltage determined by a 4 terminal geometry. The measurements are performed for Manganite and Cobaltate thin films as promising new thermoelectric materials on SrTiO3 and MgO substrates with different bulk thermal conductivity. Our results are the first steps for an optimization of the measurement configurations and the evaluation of the applicability of common analytical solutions.