Development of a wide-field magnetic domain imaging system for permanent magnets using high dynamic range synthesis technology

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04197
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21060:Electron device and electronic equipment-related
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Takezawa Masaaki 九州工業大学, 大学院工学研究院, 教授 (20312671)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: ハイダイナミックレンジ合成 / 磁気イメージング / 磁気Kerr効果 / 永久磁石 / 磁区構造

Outline of Final Research Achievements

A magnetic imaging system using synchronous shooting of multiple cameras and HDR image processing was developed to suppress 'white-out' and 'black-out' in magnetic domain observation in a wide field of view. Using this equipment, magnetic domain observation in a wide field of view and analysis of the demagnetisation process were carried out, with the aim of clarifying the relationship with the crystal structure and deriving design guidelines for high heat-resistant magnets. The equipment incorporates a double-port Kerr effect microscope and acquires magnetic domain images with different exposure times as moving images. The experimental conditions were optimized and clear magnetic domain movies of Nd-Fe-B sintered magnets during the initial magnetization process were successfully obtained. Furthermore, the magnetic domain structure changes during the thermal demagnetization process were observed and statistically analyzed.

Free Research Field

磁気工学

Academic Significance and Societal Importance of the Research Achievements

本研究では、広視野での磁区観察における「白飛び」や「黒つぶれ」を抑えるため、複数カメラの同期撮影とHDR画像処理を用いた磁気イメージング装置を開発した。この装置により、広い視野での磁区観察が可能となり、結晶組織との関連を明らかにすることで、高耐熱磁石の設計指針を導出するという学術的意義がある。さらに、減磁過程における磁区構造変化の詳細な観察と解析が可能となり、これにより新しい磁石材料の性能向上に貢献する社会的意義も持っている。この技術は産業界での応用も期待され、磁気材料の開発において重要な役割を果たすと考えられる。