Structure and thermoelectric properties of double-perovskite oxides: Sr<sub>2−</sub><i><sub>x</sub></i>K<i><sub>x</sub></i>FeMoO<sub>6</sub>
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- SUGAHARA Tohru
- The Institute of Scientific and Industrial Research Osaka University Department of Advanced Interconnection materials
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- ARAKI Teppei
- The Institute of Scientific and Industrial Research Osaka University Department of Advanced Interconnection materials
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- OHTAKI Michitaka
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University
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- SUGANUMA Katsuaki
- The Institute of Scientific and Industrial Research Osaka University Department of Advanced Interconnection materials
Bibliographic Information
- Other Title
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- Structure and thermoelectric properties of double-perovskite oxides : Sr[2−x]KxFeMoO₆
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Abstract
The thermoelectric properties of the double perovskite-type oxides Sr2−xKxFeMoO6 were investigated in terms of K-doping at the A site of the oxides. The electrical conductivity, σ, of the oxides showed a metallic behavior, decreasing monotonically from ca. 103 S/cm at room temperature to ca. 102 S/cm at 1250 K. The Seebeck coefficient, S, showed that the oxides are of n-type over the measured temperature range. The absolute value of S increased with increasing temperature. The absolute value of S at 300 K increased up to x = 0.2 and then decreased dramatically for x = 0.3–0.4. The Rietveld refinement of the XRD patterns of the oxides suggested that the increase in orbital degeneracy due to the eased distortion of FeO6 and MoO6 octahedra at x = 0.2 was responsible for the |S| maximum at this composition. The power factor, S2σ, of the oxides increased sharply with increasing K-doping level; the value for Sr1.6K0.4FeMoO6 was ca. 4.2 × 10−4 W/mK2, which is the highest among all the samples in this study. The thermal conductivity, κ, of the oxides generally decreased from ca. 3–5 W/mK at room temperature to ca. 2–4 W/mK at 1100 K. Because the power factor of the oxides increased above 900 K, the dimensionless figure of merit, ZT = S2σT/κ, increased dramatically above 900 K. The largest ZT value of 0.24 was observed for Sr1.6K0.4FeMoO6 at 1250 K.
Journal
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- Journal of the Ceramic Society of Japan
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Journal of the Ceramic Society of Japan 120 (1402), 211-216, 2012
The Ceramic Society of Japan
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Details 詳細情報について
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- CRID
- 1390001205287165568
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- NII Article ID
- 130004480063
- 40019281566
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- NII Book ID
- AA12229489
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- ISSN
- 13486535
- 18820743
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- NDL BIB ID
- 023675397
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- Text Lang
- en
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- Data Source
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- JaLC
- NDL
- Crossref
- CiNii Articles
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- Abstract License Flag
- Disallowed