Development of thermoelectric materials by novel electric-current sintering method for achieving both fine crystal grains and crystal orientation

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06861
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Material processing/Microstructural control engineering
• Research Institution: Shimane University
• Principal Investigator: Kitagawa Hiroyuki 島根大学, 学術研究院理工学系, 准教授 (00325044)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 焼結 / 結晶・組織制御 / 熱電材料

Outline of Final Research Achievements

Pulse-current sintering under cyclic uniaxial pressure was applied to Bi0.4Sb1.6Te3, which is a typical p-type thermoelectric material. The crystal alignment and grain size were remarkably changed by applying the cyclic uniaxial pressure and textures were controllable by the sintering temperature, holding time and uniaxial pressure patterns. As a result of preparation of sintered materials having the various microstructures, the texture dependence of thermoelectric properties could be shown. Furthermore, it was also confirmed that the texture and thermoelectric properties of n-type Bi2Te2.7Se0.3 could be controlled by this method as well as the p-type Bi0.4Sb1.6Te3.

Free Research Field

粉末冶金

Academic Significance and Societal Importance of the Research Achievements

本研究で対象としたBi2Te3系材料は、室温付近で動作する高性能熱電材料として知られる一方、その製造プロセスに関する研究は現在も多数行われている。本研究はユニークな材料製造プロセスを提案するとともに、組織と熱電特性の関係を示した。得られた知見が今後のBi2Te3系材料設計指針の一助となることが期待される。