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 9.25: Poster

Montag, 22. März 2010, 15:00–17:30, Poster D1

Electrical and thermal conductivity of individual cylindric nickel nanowires — •Johannes Kimling and Kornelius Nielsch — Institute of Applied Physics, University of Hamburg, Jungiusstr. 11, 20355 Hamburg

Thermoelectric nanowires (NWs) are predicted to exhibit a higher figure of merit ZT than the according bulk materials. In order to investigate the underlying physical mechanisms, measurements on individual NWs have to be realized. However due to the small length scales, electrical and thermal measurements in particular are challenging. Here, we report on measurements of the electrical and thermal conductivity of individual cylindric Ni NWs by means of 4-point measurements and by using the "3-omega self-heating" method, respectively.

Cylindric NWs of diameters between 20 nm and 400 nm are synthesized by potentiostatic electrodeposition of Ni in highly ordered alumina membranes. Before electrodeposition the pore channels of the templates were coated with silicon dioxide by means of atomic layer deposition. The silicon dioxide layer remains as a shell stabilizing the NWs after dissolution from the template.

For contact definition we use photolithography. Low contact resistances are achieved by controlled sputter etching to remove the oxide layer directly before the metallization of the electrodes. First results of a Ni NW with a radius of 180 nm show that the thermal conductivity and the Lorenz number are well below the bulk values.