Berlin 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DS: Fachverband Dünne Schichten

DS 43: Thermoelectric materials V: Bulk materials (Focused session – Organizers: Meyer, Heiliger)

DS 43.1: Topical Talk

Freitag, 30. März 2012, 13:30–14:00, H 2032

Potential Seebeck Microprobe: Considerations on Accuracy and Spatial Resolution — •Pawel Ziolkowski, Gregor Oppitz, Gabriele Karpinski, and Eckhard Müller — German Aerospace Center - Institute of Materials Research, Linder Höhe, D-51147 Köln

Recent developments turned the Potential Seebeck Microprobe (PSM) into a powerful tool for functional materials characterisation. A wide spectrum of applications was demonstrated on a variety of thermoelectric material classes involving bulk and thin film samples. The principle involves a heated probe tip positioned at the surface of a sample coupled to a heat sink. The tip is heating up the sample in a micro-vicinity, forming a locally focused temperature gradient. The thermovoltage of the sample is measured by thermocouples, which are connected to the probe tip and sample respectively and form independent circuits containing the probe-sample contact. By these circuits, thermovoltages and the temperature drop over the gradient region are recorded, yielding the local Seebeck coefficient. Here, we give a summary on the determining factors for accuracy and spatial resolution during Seebeck coefficient measurements. Furthermore a theoretical approach will be presented, which provides the possibility to enhance the spatial resolution by means of a deconvolution algorithm based on the apparatus function, which can be derived from measurements on reference samples containing sharp material property transitions. Based on the idea of this theoretical approach a successor of the PSM was designed for transient operation. First results will be presented, which shall demonstrate the enhanced spatial resolution.