Powder metallurgically synthesized Cu12Sb4S13 tetrahedrites: phase transition and high thermoelectricity. Issue 31 (29th March 2017)

• Record Type: Journal Article
• Authors: Sun, Fu-Hua; Wu, Chao-Feng; Li, Zhiliang; Pan, Yu; Asfandiyar, ; Dong, Jinfeng; Li, Jing-Feng
• Is Part Of: RSC advances. Volume 7:Issue 31(2017)
• Page Start: 18909
• Page End: 18916
• Publication Date: 2017-03-29
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra02564e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A powder metallurgical process was used to synthesise Cu12 Sb4 S13− x compounds as natural powders for use as high performance thermoelectric materials. Abstract : Cu12 Sb4 S13 tetrahedrite with intrinsically low lattice thermal conductivity has been identified as a promising thermoelectric material with earth-abundant and environmental-friendly resource, but as a natural mineral its synthesis process has not been established. This work studied a powder metallurgical process combining mechanical alloying (MA) and spark plasma sintering (SPS) to synthesize Cu12 Sb4 S13− x ( x = 0, 0.1, 0.2, 0.3 and 0.4) compounds. It is found that single-phased Cu12 Sb4 S13− x bulks could be synthesized by the MA-SPS process, but tended to become powdered naturally in air at room temperature. Interestingly, this weathering-like phenomenon could be effectively suppressed when the MA-SPS process was repeated. Consequently, a high ZT value of up to 0.65 at 723 K was achieved at a nominal composition of Cu12 Sb4 S12.7, which is close to the best value of 0.70 obtained in Cu12 Sb4 S13 tetrahedrites prepared by the melting method, although the present process is more simple and cost-effective. In addition, in this study temperature-dependent phase transitions were investigated to explore the reasons for the weathering-like phenomenon observed in synthetic Cu12 Sb4 S13 tetrahedrites.