Development of low-temperature thermoelectric materials prepared by non-thermal equilibrium reaction and optimization of its transport properties

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K14425
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Structural/Functional materials
• Research Institution: Osaka Prefecture University
• Principal Investigator: Kosuga Atsuko 大阪府立大学, 理学(系)研究科(研究院), 准教授 (30379143)
• Co-Investigator(Kenkyū-buntansha): 久保田 佳基 大阪府立大学, 理学(系)研究科(研究院), 教授 (50254371)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 熱電材料 / 非熱平衡反応 / 電気的特性 / 熱伝導率

Outline of Final Research Achievements

Metastable Ge-Sb-Te system (GST) was suggested as a potential low-temperature thermoelectric material. In this study, we prepared metastable GST bulk material by combination of melt spinning technique and room-temperature high-pressure (RTHP) pressing. The melt spun GST powder contained high ratio of the metastable phase The RTHP pressing made it possible to prepare high density of the GST bulk sample without transformation of the metastable to the stable GST phase. Our samples exhibited high Seebeck coefficient with high electrical conductivity at room temperature, which is characteristic feature of the metastable GST material. We predicted the relationship between the introduced defects and transport properties using ab-initio calculation in order to tune the transport properties of the metastable cubic GST bulk material.

Free Research Field

材料科学、無機機能材料、熱電物性

Academic Significance and Societal Importance of the Research Achievements

本研究で提案した、「非熱平衡反応を用いた準安定相バルク材料の作製法」は、熱電分野のみならず、準安定相バルク状材料を得ることでしか、物性が得られないような分野にも応用できることから、これまで明らかになっていない基礎物性の解明に繋がる可能性があるという点で意義がある。また、本研究をさらに発展させ、高い熱電特性をもつ材料が今後開発できれば、マイナス温度域の廃熱回収技術の一端を担うという意味で、社会的にも重要な研究に繋がると期待できる。