Study of thermal stability of p-type skutterudites DD0.7Fe3CoSb12 by Knudsen effusion mass spectrometry

František Zelenka; Pavel Brož; Jan Vřešťál; Jiří Buršík; Gerda Rogl; Andriy Grytsiv; Peter Rogl

doi:10.1039/c9ra04056k

Study of thermal stability of p-type skutterudites DD_0.7Fe₃CoSb₁₂ by Knudsen effusion mass spectrometry

RSC Adv. 2019 Jul 9;9(37):21451-21459. doi: 10.1039/c9ra04056k. eCollection 2019 Jul 5.

Authors

František Zelenka^{1

2}, Pavel Brož^{1

2}, Jan Vřešťál^{1

2}, Jiří Buršík³, Gerda Rogl^{4

5}, Andriy Grytsiv^{4

5}, Peter Rogl^{4

5}

Affiliations

¹ Masaryk University, Faculty of Science, Department of Chemistry Kotlářská 2 61137 Brno Czech Republic broz@chemi.muni.cz.
² Masaryk University, Central European Institute of Technology, CEITEC Kamenice 753/5 62500 Brno Czech Republic.
³ Institute of Physics of Materials, Czech Academy of Sciences Žižkova 22 61662 Brno Czech Republic.
⁴ Institute of Materials Chemistry, University of Vienna Währingerstraße 42 A-1090 Vienna Austria.
⁵ Christian Doppler Laboratory for Thermoelectricity Vienna Austria.

Abstract

The temperature and phase stability of p-type skutterudites, DD_0.7Fe₃CoSb₁₂, manufactured via various preparation techniques, all exhibiting a high ZT-level, have been studied by means of thermal analysis and Knudsen effusion mass spectrometry. The results from phase transformation measurements and characteristics of the evaporation of antimony, as the volatile element, supported by microstructure observations and by diffusion profiles are summarized and discussed in view of a full understanding of the degradation processes and knowledge of the long term operation stability of the bulk and nano-structured thermoelectrics studied. It was found out that the antimony evaporation is a complex diffusion kinetic process resulting in a stable Sb level dependent on the preparation route. The studied p-type skutterudites, DD_0.7Fe₃CoSb₁₂, have proven their long term stability in thermoelectric devices at a maximum operation temperature of 600 °C. Complementary data on the structural, physical and mechanical properties of the materials are presented as well.