Elucidation and control of nanoscale thermal transport in spin caloritronics

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20495
• 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: HIRAI Takamasa 国立研究開発法人物質・材料研究機構, 磁性・スピントロニクス材料研究センター, 研究員 (30949863)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: スピンカロリトロニクス / 熱伝導 / 時間領域サーモリフレクタンス / スピン流 / 熱電変換 / 金属人工格子 / 磁性薄膜

Outline of Final Research Achievements

In this study, we have constructed a unique thermal conductivity measurement system that allows to change the measurement temperature and apply an external field, aiming to create a new functionality to control thermal energy by interfusing spin caloritronics and thermal transport in solids: heat conduction. The following results were obtained through the thermal conductivity measurements mainly by focusing on the interface control of magnetic ultrathin films. (1) Demonstration of spin current-mediated control of nanoscale thermal transport at room temperature, (2) Establishment of a high-throughput material exploration for transverse magneto-thermoelectric conversion and demonstration of its zero-field-operation, (3) Observation of reducing the thermal conductivity in Fe/Pt metallic superlattices and quantitative evaluation of dimensionless figure of merit for transverse thermoelectric conversion.

Free Research Field

スピントロニクス

Academic Significance and Societal Importance of the Research Achievements

本研究では、スピントロニクス材料の熱伝導率の汎用性の高い計測・評価法を確立し、スピンカロリトロニクスでは未開拓であった磁性/スピンを利用した熱輸送制御機能の創出に先鞭をつけることに成功した。本研究成果を基盤として、電子・フォノン・スピンなど複数の熱キャリアによって媒介される熱伝導の物理描像の総合的な理解の進展や更なる新たな熱伝導制御機能の開拓、それらに最適な物質探索の活性化などに結び付く可能性があり、学術的・社会的意義は極めて大きい。