Constitution of the binary M-Sb systems (M = Ti, Zr, Hf) and physical properties of MSb2

A. Tavassoli, A. Grytsiv, F. Failamani, G. Rogl, S. Puchegger, H. Müller, P. Broz, F. Zelenka, D. Macciò, A. Saccone, G. Giester, E. Bauer, M. Zehetbauer, P. Rogl

Index: 10.1016/j.intermet.2017.12.014

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Abstract

This study is closely related to the chemical interactions in thermoelectric joints of a hot metal electrode with p- and n-type skutterudite. As a result of this work, a first and complete phase diagram has been constructed for the Ti Sb system as well as partial phase diagrams (>65 at.% Sb) for the systems Zr Sb and Hf Sb. Investigations are based on X-ray powder and single crystal analyses (determination of the crystal structure of Ti5Sb8 with Zr2.6Ti2.4Sb8-type, space group I4122; RF = 0.032), electron probe microanalyses (EPMA) and differential thermal analyses (DTA). Physical properties were evaluated for the binary compounds MSb2 (M = Ti, Zr, Hf) comprising electrical resistivity (from 4.2 K to 825 K), specific heat, thermal conductivity and thermal expansion coefficient (from 4.2 K to 300 K), Seebeck coefficient (from 300 K to 825 K) and elastic moduli at 300 K. These data will serve to evaluate the potential of MSb2 compounds (M = Ti, Zr, Hf) for thermoelectric devices, where these phases predominantly appear in the diffusion zones of the hot metal electrode with p- and n-type skutterudite.