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Thermoelectric properties of Ru and In substituted misfit-layered Ca3Co4O9

Published online by Cambridge University Press:  14 August 2013

Gesine Saucke
Affiliation:
Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Solid State Chemistry and Catalysis, Überlandstr. 129, CH-8600 Dübendorf, Switzerland
Sascha Populoh
Affiliation:
Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Solid State Chemistry and Catalysis, Überlandstr. 129, CH-8600 Dübendorf, Switzerland
Nina Vogel-Schäuble
Affiliation:
Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Solid State Chemistry and Catalysis, Überlandstr. 129, CH-8600 Dübendorf, Switzerland
Leyre Sagarna
Affiliation:
Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Solid State Chemistry and Catalysis, Überlandstr. 129, CH-8600 Dübendorf, Switzerland
Kailash Mogare
Affiliation:
University of Berne, Department of Chemistry and Biochemistry, CH-3012 Berne, Switzerland
Lassi Karvonen
Affiliation:
Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Solid State Chemistry and Catalysis, Überlandstr. 129, CH-8600 Dübendorf, Switzerland
Anke Weidenkaff
Affiliation:
Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Solid State Chemistry and Catalysis, Überlandstr. 129, CH-8600 Dübendorf, Switzerland University of Berne, Department of Chemistry and Biochemistry, CH-3012 Berne, Switzerland
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Abstract

As an approach to improve the thermoelectric properties of the polycrystalline Ca3Co4O9 misfit-layered oxide, substitutions of Co2+…4+ with the heavier cations Ru3+/4+ and In3+ were tested. Polycrystalline samples Ca3Co4-xRuxO9 and Ca3Co4-xInxO9 (0 < x < 0.21) were prepared via a solid-state-reaction route. For each sample the crystal structure was analyzed and a complete thermoelectric characterization was done within a temperature range of 300 K < T < 1125 K.

Both substitution strategies resulted in a significant decrease of the thermal conductivity (κ). For the In3+-substituted samples the decrease of the Seebeck coefficient (α) balanced the κ reduction so that no overall enhancement of the figure of merit (ZT) was found. The Ru3+/4+ substitution reduced the p-type carrier concentration and thus increases the electrical resistivity (ρel), while α became larger at low temperatures. Despite the reduction of the power factor, a small enhancement in ZT was observed in the case of x = 0.1 Ru substitution, due to the strong κ reduction. Considering the observed preferred orientation of the Ru-substituted crystallites, a maximum value of ZT = 0.14 perpendicular to the pressing direction is found at T = 1125 K, indicating that Ru substitution is a promising strategy for a further ZT improvement.

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Articles
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

He, J., Liu, Y., Funahashi, R., Journal of Materials Research 26(15), 1762 (2011).CrossRefGoogle Scholar
Bruce, D.W., O'Hare, D., Walton, R.I., Functional oxides - Chapter 4: Thermoelectric Oxides (Wiley, Chichester, 2010)CrossRefGoogle Scholar
Fergus, J.W., Journal of the European Ceramic Society 32(3), 525 (2012).CrossRefGoogle Scholar
Shikano, M., Funahashi, R., Applied Physics Letters 82(12), 1851 (2003).CrossRefGoogle Scholar
Nong, N., Liu, C., Ohtaki, M., Journal of Alloys and Compounds 491(1-2), 53 (2010).CrossRefGoogle Scholar
Moser, D., Karvonen, L., Populoh, S., Trottmann, M., Weidenkaff, A., Solid State Sciences 13(12), 2160 (2011).CrossRefGoogle Scholar
Wang, Y., Xu, L., Sui, Y., Wang, X., Cheng, J., Su, W., Applied Physics Letters 97(6), 062114 (2010).CrossRefGoogle Scholar
Yao, Q., Wang, D.L., Chen, L.D., Shi, X., Zhou, M., Journal of Applied Physics 97(10), 103905 (2005).CrossRefGoogle Scholar
Populoh, S., Aguirre, M., Brunko, O., Galazka, K., Lu, Y., Weidenka, A._, Scripta Materialia 66(12), 1073 (2012).CrossRefGoogle Scholar
Masset, A.C., Michel, C., Maignan, A., Hervieu, M., Toulemonde, O., Studer, F., Raveau, B., Hejtmanek, J., Physical Review B 62(1), 166 (2000).CrossRefGoogle Scholar
Snyder, G.J., Toberer, E.S., Nature Materials 7(2), 105 (2008).CrossRefGoogle Scholar
Wang, Y., Sui, Y., Cheng, J., Wang, X., Su, W., Journal of Physics: Condensed Matter 19(35), 356216 (2007).Google Scholar
Toberer, E.S., Zevalkink, A., Snyder, G.J., Journal of Materials Chemistry 21(40), 15843 (2011).CrossRefGoogle Scholar
Xie, W., He, J., Zhu, S., Holgate, T., Wang, S., Tang, X., Zhang, Q., Tritt, T.M., Journal of Materials Research 26(15), 1791 (2011).CrossRefGoogle Scholar
For the laser flash measurement the lamella were put into a square-shaped sample holder and the upper side was coated with an Ethanol - Ca3Co4O9 slurry, sprayed on the lamella with an airbrush (A709 by AZTEK), to fill the small gaps between the lamella. The cobalt oxide powder for the slurry was produced through a soft chemistry method.Google Scholar
Zhang, L., Okinaka, N., Tosho, T., Akiyama, T., Journal of Optoelectronics and advanced materials 14(1-2), 67 (2012)Google Scholar