Fast and scalable preparation of tetrahedrite for thermoelectrics via glass crystallization

A Cu12Sb3.6Bi0.4S10Se3 glass was prepared by melt spinning and crystallized by heat treatments at selected temperatures, the total preparation procedure taking less than one day. The sample characterization by powder X-ray diffraction, scanning and transmission electron microscopy complemented with EDS indicate the formation of compact materials, with a tetrahedrite relative weight fraction higher than 90% when treated at temperatures close to the crystallization peaks (similar to 200 degrees C). Selenium enters the tetrahedrite structure, while bismuth precipitates in submicron and nanosized spherical shape phases depleted in copper and enriched in antimony, sulfur and selenium (when compared with the matrix composition). The characterization of electrical transport properties (electrical resistivity and Seebeck coefficient) indicate a behavior similar to that obtained by other methods on Cu12Sb4S13, with a maximum power factor of similar to 400 mW/K(2)m at room temperature. (c) 2015 Elsevier B.V. All rights reserved.