Development of an x-ray magnetic microscope aiming observation of magnetic domains inside materials

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H04405
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 80040:Quantum beam science-related
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: Inami Toshiya 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 放射光科学研究センター, 上席研究員 (30354989)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 磁気光学効果 / X線磁気円偏光発光 / 円偏光 / 特性X線 / 電磁鋼板 / 磁区 / 磁気顕微鏡

Outline of Final Research Achievements

Functional magnetic materials are widely used in crucial devices that support our life. For instance, electrical steel sheets and/or permanent magnets are important components of motors, generators and transformers. To improve the magnetic properties of these materials, elucidation of the structure and motion of the magnetic domains (small areas in which all the magnetic moments are parallel to each other) under magnetic fields is indispensable. Nevertheless, the measurement of magnetic domains well below the surface of thick samples has been a longstanding problem. X-ray magnetic circularly polarized emission (XMCPE) is a new magneto-optical effect discovered in 2017, which is highly sensitive to the magnetism of 3d transition metal elements in the hard X-ray regime, where the penetration length is very long. In this study, a magnetic microscope that utilizes XMCPE was developed and magnetic domains well below the surface of an electrical steel sheet were successfully observed.

Free Research Field

磁性

Academic Significance and Societal Importance of the Research Achievements

本研究では、表面近傍だけでなく、物質内部の磁区（磁気モーメントが一方向にそろった小さな領域）を観察できる磁気顕微鏡を開発した。金属など不透明な磁性体の内部の磁区観察は長年の課題であり、これまで材料内部の磁区は計算による推定や想像でしかなかった。実験的に内部の磁区を直接観察できれば、磁気特性の理解を進めることにつながり、学術的な意義は大きい。さらに、ここから実際の機能性磁性材料の特性向上につなげることができれば、機能性磁性材料が広く我々の生活に関わっていることから、大きな省エネルギー、省資源効果が期待でき、社会的意義にもつながる。