Elucidation of physical properties of spin current thermoelectric phenomena using magnetic insulator thin films fabricated by wet process

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05255
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 28020:Nanostructural physics-related
• Research Institution: Gifu University
• Principal Investigator: Yamada Keisuke 岐阜大学, 工学部, 助教 (50721792)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: スピンゼーベック効果 / 磁性ナノ粒子 / 微細構造 / 共沈法 / ゾルゲル法 / グラニュラー / 化学合成プロセス / 熱電変換効率

Outline of Final Research Achievements

We have fabricated a magnetic thin film composed of nanoparticles by using a chemical fabrication method, and measured the spin Seebeck effect (SSE) and correlated the physical properties of the structure, magnetic properties, and SSE voltage. The purpose of our study is the elucidation of each correlation. (1) In the YIG films prepared by the coprecipitation method, the correlation between the fine structure of the sample and the SSE electromotive force was clarified. (2) In the Bi-YIG films fabricated by the sol-gel method, the spin current conversion efficiency for the Bi-YIG samples increased due to Bi substitution, and the SSE voltage also increased. (3) YIG-Pt granular films were prepared by coprecipitation method and polyol method, and the thermoelectric conversion performance was improved by increasing the ratio of Pt fine particles. We could not only clarify the physical properties of SSE, but also show a technology that can contribute to energy harvesting technology.

Free Research Field

スピントロニクス

Academic Significance and Societal Importance of the Research Achievements

本研究の成果の学術的意義は、様々な化学的プロセスを用いて磁性ナノ粒子を作製、薄膜化し、結晶構造、微細構造、磁気特性、スピン流熱電現象の相関を明らかにしたことである。このことは簡易かつ大量生産が化学プロセスを用いた試料作製によっても、十分にスピン熱電現象が得られることを示した結果で、応用展開や開発の指針となる。また世界で先駆けて化学プロセスによって作製した試料でスピン流熱電現象の観測に成功したことは今後の研究展開にも大きな期待をもてる。