Effect of Element Substitution at V site on Thermoelectric Properties of Aurivillius Phase Bi2VO5.5
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- 作者：Hitoshi Kohri ; Takayoshi Yagasaki
- 关键词：Aurivillius compound ; Bi layered oxide ; oxygen ion conductor ; thermoelectric oxide
- 刊名：Journal of Electronic Materials
- 出版年：2016
- 出版时间：October 2016
- 年：2016
- 卷：45
- 期：10
- 页码：4928-4934
- 全文大小：2,030 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Optical and Electronic Materials
Characterization and Evaluation Materials
Electronics, Microelectronics and Instrumentation
Solid State Physics and Spectroscopy - 出版者：Springer Boston
- ISSN：1543-186X
- 卷排序：45
文摘
Thermoelectric oxides are suitable at the high temperature range because of chemical stability. Aurivillius compounds are bismuth layered oxides, and known as oxygen ion conductors. The Aurivillius compounds consist of Perovskite layers and Bi-O layers. It is expected that nano-layered structure shows high Seebeck coefficients due to the quantum confinement of carriers in Perovskite layers. It was reported that the Seebeck coefficient of hot pressed specimens for Aurivillius phase Bi2VO5.5 was a high value of −28.3 mVK−1 at 1010 K, and the electrical resistivity of one was also a high value of 0.033 Ωm at 1010 K. In this paper, the effect of element substitution at the V site on thermoelectric properties of Aurivillius phase Bi2VO5.5 was investigated. Bi2V1−xMxO5.5 (M = Cr, Mo, W x = 0, 0.05, 0.1, 0.2) were prepared by solid-state reaction. The electrical resistivity of Cr-substituted specimens were indicated at larger values than the ones for unsubstituted specimens over the measurement temperature range. The resistivity above 800 K was reduced by substitution of W or Mo. W as a substituted element was effective for reducing the thermal conductivity of Bi2VO5.5. The maximum value of the dimensionless figure of merit ZT was 0.05 at 799 K for Bi2V0.8Mo0.2O5.5 and at 902 K for Bi2V0.8W0.1O5.5. The maximum ZT of an unsubstituted sample was 0.02 at 993 K. From these results, it was found that tungsten or molybdenum substitution was effective to improve ZT for Aurivillius phase Bi2VO5.5.