Substitution of Antimony by Tin and Tellurium in n-Type Skutterudites CoSb2.8Sn x Te0.2−x

• DOI: 10.1007/s11837-014-1146-1
• Publication Date: 2014-09-15T12:29:26Z
• Authors: Tulashi Dahal; Yucheng Lan; Qing Jie; Weishu Liu; Keshab Dahal; Lu Tang; Chuanfei Guo; Zhifeng Ren
• Keywords: 0211 other engineering and technologies; 02 engineering and technology; 7. Clean energy

We have studied the substitution of antimony by tin and tellurium in n-type skutterudites CoSb2.8Sn x Te0.2−x . The samples were made by ball milling ingots and hot pressing the ball-milled nanopowder. Rather than filling the cage of the structure, we aimed to use disorder in pnictogen rings by elemental substitution of Sb by Sn and Te. In skutterudite CoSb3, the dominant heat-carrying phonons are associated with the vibrational modes of the Sb-rings; disorder in the rings can be an effective way to suppress the thermal transport. By suitably tuning the contents of Sn and Te in the skutterudites, we have suppressed the thermal conductivity and achieved a power factor of ~42 μW cm−1 K−2 at 530°C. A peak thermoelectric figure of merit (ZT) reaches ~1.1 at 530°C for CoSb2.8Sn0.005Te0.195. This ZT value is comparable with that of some of the single-filled skutterudites.