Modeling the Thermoelectric Properties of Tib class="a-plus-plus">5b>Ob class="a-plus-plus">9b> Magnéli Phase Ceramics

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• 作者：Sudeep J. Pandey ; Giri Joshi ; Shidong Wang…
• 关键词：Thermoelectrics ; nanoceramics ; magnéli phase ; small polaron ; Ti5O9
• 刊名：Journal of Electronic Materials
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：45
• 期：11
• 页码：5526-5532
• 全文大小：1,537 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry<br>Optical and Electronic Materials<br>Characterization and Evaluation Materials<br>Electronics, Microelectronics and Instrumentation<br>Solid State Physics and Spectroscopy<br>
• 出版者：Springer Boston
• ISSN：1543-186X
• 卷排序：45

文摘

Magnéli phase Tib>5b>Ob>9b> ceramics with 200-nm grain-size were fabricated by hot-pressing nanopowders of titanium and anatase TiOb>2b> at 1223 K. The thermoelectric properties of these ceramics were investigated from room temperature to 1076 K. We show that the experimental variation of the electrical conductivity with temperature follows a non-adiabatic small-polaron model with an activation energy of 64 meV. In this paper, we propose a modified Heikes-Chaikin-Beni model, based on a canonical ensemble of closely spaced titanium tb>2gb> levels, to account for the temperature dependency of the Seebeck coefficient. Modeling of the thermal conductivity data reveals that the phonon contribution remains constant throughout the investigated temperature range. The thermoelectric figure-of-merit ZT of this nanoceramic material reaches 0.3 K at 1076 K.