Effect of Composition on Thermoelectric Properties of As-Cast Materials: The Cu12−xCoxSb4S13−ySey Case

• Published in: Journal of electronic materials 2019-04, Vol.48 (4), p.2028-2035
• Main Authors: Alves, Tiago Kalil Cortinhas, Domingues, Gonçalo, Branco Lopes, Elsa, Pereira Gonçalves, António
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Electronics and Microelectronics; Instrumentation; International Conference on Thermoelectrics 2018; Materials Science; Optical and Electronic Materials; Solid State Physics; Topical Collection: International Conference on Thermoelectrics 2018
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-019-06956-7

Samples with Cu 12− x Co x Sb 4 S 13− y Se y (0 ≤  x  ≤ 2, 0 ≤  y  ≤ 1) nominal compositions were prepared by melting the elements under vacuum, followed by slow cooling. The phases formed in this process were identified and characterized by powder x-ray diffraction and scanning electron microscopy observations, complemented with energy-dispersive spectroscopy. All samples have tetrahedrite as the major phase (> 78 vol.%). However, minority phases like skinnerite and chalcostibite are usually also observed, the number and volume of them increasing with the increase of cobalt content. Measurements of electrical resistivity and Seebeck coefficient showed that these materials can present large power factors, with the Cu 11.5 Co 0.5 Sb 4 S 12 Se sample having a room temperature value higher than 200  μ W K −2  m −1 .