Structure and thermoelectric properties of Cs-Bi-Te alloys fabricated by different routes of reduction of oxide reagents

Cesium-bismuth-telluride polycrystalline materials were fabricated using a cost-effective method based on a reduction of oxide reagents, leading to a production of a material with good thermoelectric properties. Several samples with various initial stoichiometry were prepared by melting of oxide powders at 1050 °C, quenching, milling to powders and then reducing in pure hydrogen at 400 °C. Another concept was to obtain the CsBi4Te6 material without a melting stage. Composition of the samples was analyzed by the XRD and EDX methods. The sample with 96% of CsBi4Te6 phase was obtained in a way of reduction of oxide reagents. Thermoelectric properties of fabricated samples were also investigated.