Effect of hot pressing on the microstructure and thermoelectric properties of TGZM-grown YbFe-doped CoSb3 skutterudite. Issue 7 (1st April 2021)

• Record Type: Journal Article
• Authors: Li, Xuguang; Li, Shuangming; Li, Dou; Yang, Bin; Xu, Changjiang; Zhong, Hong
• Is Part Of: Ceramics international. Volume 47:Issue 7(2021)Part A
• Page Start: 8949
• Page End: 8958
• Publication Date: 2021-04-01
• Subjects: CoSb3 -- Temperature gradient zone melting -- Hot processing -- Thermoelectric properties; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.12.017
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Skutterudites based on CoSb3 are considered potential candidates in thermoelectric applications in the field of mid-temperature power generation. The annealing process necessitates more than a week to complete the peritectic phase transition for traditional melting-quenching-annealing-sintering methods. Herein, a new strategy combining the temperature gradient zone melting process with hot pressing (TGZM-HP) was successfully employed to synthesize YbFe-doped p-type CoSb3 in a shorter time. The resulting samples show enhanced thermoelectric properties compared to TGZM-grown ones, especially in the case of 1 at.% YbFe-doped CoSb3 . This compound exhibits a maximal Seebeck coefficient of 166.3 μVK −1 and a power factor of 1.8 mWm −1 K −2 at 723 K, showing an increase in these values of 25% and 51%, respectively. Moreover, phonon scattering appears to be enhanced due to the significant reduction in the grain size of the TGZM-HP samples, resulting in a minimum thermal conductivity of 2.71 Wm −1 K −1 . A dimensionless figure of merit ( ZT ) of 0.48 was obtained for 1 at.% YbFe-doped CoSb3 . This value is 1.6 times larger than that measured for TGZM-grown CoSb3 . This work provides an alternative strategy to fabricate skutterudite materials and foster their development.