Category: Transient Plane Source
Keywords: electrical resistance, Thermal Conductivity, Thermoelectric Materials, Thermopower, Transient Plane Source Technique, Type E Differential Thermocouple, van der Pauw Method, X-ray Diffraction, X-ray diffraction (XRD), XRD
Abstract: Thermoelectric materials are currently being researched as a source of energy in order to reduce carbon dioxide emissions. The efficiency of these materials depends on their Seebeck coefficient, electrical resistivity, and thermal conductivity, as well as the absolute temperature. Cobalt oxides (Ca3Co4O9+delta) have been researched extensively as potential thermoelectric materials because of their high Seebeck coefficient and low electrical resistivity and thermal conductivity. Systems have been studied with partial replacement of the cations in either the calcium or the cobalt sites and it has been found that partial replacement of calcium with bismuth improved the electrical conductivity. The same is true for the partial replacement of cobalt with iron. This article examined the thermoelectric properties of systems involving the partial replacement of calcium and cobalt with bismuth and iron respectively. It was found that the Ca2.9Bi0.1Co3.9Fe0.1O9+delta sample gave the highest thermopower, as well as the highest figure of merit (measure of efficiency for thermoelectric materials) of all the samples that were tested.
Reference: Journal of Materials Science - Materials in Electronics, 25, 2 (2014) 778-784