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arXiv · 1209.1250

High-temperature thermoelectric properties of the double-perovskite ruthenium oxide (Sr$_{1-x}$La$_x$)$_2$ErRuO$_6$

Ryohei Takahashi·Ryuji Okazaki·Yukio Yasui·Ichiro Terasaki·Takaaki Sudayama·Hironori Nakao·Yuichi Yamasaki·Jun Okamoto·Youichi Murakami·Yoshinori Kitajima
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Abstract

We have prepared polycrystalline samples of (Sr$_{1-x}$La$_x$)$_2$ErRuO$_6$ and (Sr$_{1-x}$La$_x$)$_2$YRuO$_6$, and have measured the resistivity, Seebeck coefficient, thermal conductivity, susceptibility and x-ray absorption in order to evaluate the electronic states and thermoelectric properties of the doped double-perovskite ruthenates. We have observed a large Seebeck coefficient of -160 $\mu$V/K and a low thermal conductivity of 7 mW/cmK for $x$=0.1 at 800 K in air. These two values are suitable for efficient oxide thermoelectrics, although the resistivity is still as high as 1 $\Omega$cm. From the susceptibility and x-ray absorption measurements, we find that the doped electrons exist as Ru$^{4+}$ in the low spin state. On the basis of the measured results, the electronic states and the conduction mechanism are discussed.

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Ryohei Takahashi, Ryuji Okazaki, Yukio Yasui, Ichiro Terasaki, Takaaki Sudayama, Hironori Nakao, Yuichi Yamasaki, Jun Okamoto, Youichi Murakami, Yoshinori Kitajima. 2012-09-06. High-temperature thermoelectric properties of the double-perovskite ruthenium oxide (Sr$_{1-x}$La$_x$)$_2$ErRuO$_6$. https://doi.org/10.1063/1.4757632

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