Thermomigration and Soret effect in Na_xCoO₂ as thermoelectric material: Preparation and characterization of sodium cobaltate thin films (Phys. Status Solidi A 5∕2016)

Abstract

Thermomigration (Ludwig‐Soret effect) can significantly influence the properties of thermoelectric materials by locally changing the charge carrier concentrations and, therefore, the figure of merit. The study by Schneider et al. (pp. http://doi.wiley.com/10.1002/pssa.201532725) deals with evolving sodium concentration gradients by applying a temperature gradient parallel to the natural layered structure of epitaxially grown NaxCoO2. A self‐designed experimental set‐up enables both the evaluation of the heat of transport and the chemical diffusion coefficient. The results represent one of the very rare examples of the Soret effect in thermoelectric materials.