Strain-induced magnetization switching for magnetic single crystal thin film grown on freestanding membrane

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K18894
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Tohoku University
• Principal Investigator: Seki Takeshi 東北大学, 金属材料研究所, 教授 (40579611)
• Co-Investigator(Kenkyū-buntansha): 塩貝 純一 大阪大学, 大学院理学研究科, 准教授 (30734066)
• Project Period (FY): 2022-06-30 – 2024-03-31
• Keywords: 歪み / 磁気異方性 / 自立型メンブレン

Outline of Final Research Achievements

This study has paid attention to the usefulness of single-crystal like magnetic thin films grown on freestanding membranes and carried out research focusing on elucidating their magnetic properties.
First, the conditions for epitaxial growth on freestanding membranes were investigated for the Ni and Fe4N layers and established a method for evaluating magnetic properties under the application of strain. The changes in magnetic anisotropy, saturation magnetization, and ferromagnetic transition temperature due to strain were successfully observed. The obtained experimental results also suggested that epitaxially grown thin films are effective to evaluate antisymmetric exchange interactions caused by lattice deformation. In addition, ferromagnetic materials exhibiting a larger magnetoelastic effect were explored, and the epitaxial thin films of Fe-Ga alloys were successfully developed.

Free Research Field

磁性材料学

Academic Significance and Societal Importance of the Research Achievements

ウェアラブルやユビキタスを支えるフレキシブル電子デバイスの高性能化・多機能化は、今後の持続可能な社会づくりの鍵となる。磁性体における歪みを使ってデバイスの新機能を見出すためには、薄膜形態において歪みの影響を理解することが不可欠である。
本研究は、「単結晶」かつ「柔らかい」という特性を活用できる自立型メンブレンに着目し、自立型メンブレンを使った薄膜の成長条件や評価技術を確立し、歪みによる基本的な磁気特性の変調に成功した。磁気弾性特性の理解を深化させる学術的に意義深い成果である。また、歪みを使った新しい磁化スイッチング技術の開発指針を与えるものでもあり、応用の観点でも意義のある成果と言える。