Elucidation of the mechanism of high Seebeck coefficient by using galvano- and thermo-magnetic effect measurement

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15297
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Murata Masayuki 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 主任研究員 (80717695)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 熱電変換 / 熱磁気効果 / 磁気抵抗効果 / 磁場効果 / ナノワイヤー

Outline of Final Research Achievements

In this study, we first established a technique to measure the thermo-magnetic effects such as the magnetic Seebeck effect and the Nernst effect, the galvano-magnetic effects such as the magnetoresistance effect and the Hall effect, and the thermal conductivity in a magnetic field. In nanowires, we measured the magnetic Seebeck effect and the magnetoresistance effect, and found that the effect of the change in the scattering mechanism of carriers on the Seebeck coefficient was limited. In materials with multiple carriers, we found that the scattering mechanism cannot be determined independently, because the Nernst coefficient depends not only on the scattering mechanism but also on the electric conductivity ratio of the carriers.

Free Research Field

熱電変換

Academic Significance and Societal Importance of the Research Achievements

熱電変換材料とは、「電気」と「温度差」を相互に直接変換できる材料であり、材料に電流を印加する事で温度差が生じ、逆に温度差を与えることで起電力が生じる。この材料は、小型温冷庫や高精度温調、環境発電や非常用電源として使われている。材料の高性能化によって冷却素子の消費電力の低下や、発電素子のエネルギー変換効率の向上が見込まれ、需要の大きい室温領域での高性能化により早急な市場の拡大が期待できる。本研究では材料の熱磁気効果や電流磁気効果の測定により、材料の熱電性能と詳細な物性の関係を明らかにし、材料開発指針へ寄与することができる。