Solution-based synthesis routes to thermoelectric Bi 2Ca 2Co 1.7O x

Abstract

The synthesis of Bi 2Ca 2Co 1.7O x misfit compounds by different processing routes, i.e. classical solid-state, and two solution methods namely sol–gel via nitrates and a polymer route, has been investigated. A comparison among the final products has been performed using DTA, TGA, X-ray diffraction, scanning electron microscopy, and thermoelectric characterizations. All the samples obtained by solution synthesis show a very important increase in ZT, as compared to the solid state prepared samples, due to a significant decrease in the electrical resistivity values.