Seebeck-driven transverse magneto-thermoelectric generation in magnetic / thermoelectric composite materials

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20494
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0402:Nano/micro science, applied condensed matter physics, applied physics and engineering, and related fields
• Research Institution: National Institute for Materials Science
• Principal Investigator: Zhou Weinan 国立研究開発法人物質・材料研究機構, 若手国際研究センター, ICYSリサーチフェロー (20961593)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: 横熱電効果 / スピンカロリトロニクス / 熱電変換 / 異常ネルンスト効果 / 磁性材料

Outline of Final Research Achievements

This project aims to realize large transverse thermopower with Seebeck-driven transverse magneto-thermoelectric generation, where magnetic and thermoelectric materials are combined to create new composite materials. For this purpose, we focused on the simplest way to combine a magnetic material and a thermoelectric material, i.e., stacking a magnetic layer and a thermoelectric layer together to form a bilayer. We derived the expression for its transverse thermopower, which varies with the thickness of the layers, and peaks at a certain thickness ratio. This prediction was well reproduced in the experiment. The sample with the proper thickness ratio showed transverse thermopower much larger than that of the magnetic material.

Free Research Field

スピンカロリトロニクス

Academic Significance and Societal Importance of the Research Achievements

本研究では，熱電材料と磁性材料を積層しただけのシンプルな構造において，ゼーベック駆動横型磁気熱電効果を利用して大きな横熱電能が得られることを実証した．積層構造のトランスポート特性における計算値と実験結果の良い一致から，複合材料を設計する際の重要な知見が得られた．従来熱電材料と磁性材料を組み合わせる際に使う閉回路構造と比べて積層構造が作りやすく応用上の汎用性が高いため，これを活用した新しい環境発電技術や高感度な熱流センサなどへの展開が期待される．