Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published February 2014 | Published
Journal Article Open

Phase diagram of In–Co–Sb system and thermoelectric properties of In-containing skutterudites


In-containing skutterudites have long attracted much attention and debate partly due to the solubility limit issue of indium in CoSb_3. The isothermal section of the equilibrium phase diagram for the In–Co–Sb system at 873 K is proposed using knowledge of the related binary phase diagrams and experimental data, which explains the debated indium solubility that depends on Sb content. In this paper, a series of In-containing skutterudite samples (In_xCo_4Sb_(12−x/3) with x varying from 0.075 to 0.6 and In_(0.3)Co_(4−y)Sb_(11.9+y) with y changing from −0.20 to 0.20) are synthesized and characterized. X-ray analysis and scanning electron microscopy images indicate that, up to x = 0.27, single-phase skutterudites are obtained with lattice constant increasing with In fraction x. A fixed-composition skutterudite In_(0.27±0.01)Co_4Sb_(11.9) was determined for the Co-rich side of In–CoSb_3 which is in coexistence with liquid InSb and CoSb_2. Indium, like Ga, is expected, from DFT calculations, to form compound defects in In-containing skutterudites. However, relatively higher carrier concentrations of In-containing skutterudites compared to Ga-containing skutterudites indicate the existence of not fully charge-compensated compound defects, which can also be explained by DFT calculations. The net n-type carrier concentration that naturally forms from the complex defects is close to the optimum for thermoelectric performance, enabling a maximum zT of 1.2 for the fixed skutterudite composition In_(0.27)Co_4Sb_(11.9) at 750 K.

Additional Information

© 2014 Royal Society of Chemistry. Received 29th September 2013. Accepted 2nd December 2013. This work is partially supported by National Basic Research Program of China (973-program) under Project no.2013CB632501, National Natural Science of Foundation of China (NSFC) under the no. 11234012, 51121064, and 51222209. The authors acknowledge the financial support of National Science Council of Taiwan (NSC101-3113-P-008-001).

Attached Files

Published - c3ee43240h.pdf


Files (1.6 MB)
Name Size Download all
1.6 MB Preview Download

Additional details

August 19, 2023
October 26, 2023