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arXiv · 0806.2506

Origin of large thermopower in LiRh$_2$O$_4$

R. Arita·K. Kuroki·K. Held·A. V. Lukoyanov·S. Skornyakov·V. I. Anisimov
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Abstract

Motivated by the newly synthesized mixed-valent spinel LiRh$_2$O$_4$ for which a large thermopower is observed in the metallic cubic phase above 230K [Okamoto {\it et al.} (arXiv:0806.2504)], we calculate the Seebeck coefficient by the combination of local density approximation and dynamical mean field theory (LDA+DMFT). The experimental values are well reproduced not only by LDA+DMFT but also by the less involved Boltzmann equation approach. A careful analysis of the latter shows unexpectedly that the origin of the large thermopower shares a common root with a very different oxide: Na$_x$CoO$_2$. We also discuss how it is possible to further increase the powerfactor of LiRh$_2$O$_4$ through doping, which makes the material even more promoising for technological applications.

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R. Arita, K. Kuroki, K. Held, A. V. Lukoyanov, S. Skornyakov, V. I. Anisimov. 2008-10-01. Origin of large thermopower in LiRh$_2$O$_4$. https://arxiv.org/abs/0806.2506

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