XMCD reflectivity measurement to elucidate magnetic structure in multilayer thin films

Research Project

Project/Area Number	21K14539
Research Category	Grant-in-Aid for Early-Career Scientists
Allocation Type	Multi-year Fund
Review Section	Basic Section 29020:Thin film/surface and interfacial physical properties-related
Research Institution	National Institutes for Quantum Science and Technology (2023) Institute for Molecular Science (2021-2022)
Principal Investigator	Yamamoto Kohei 国立研究開発法人量子科学技術研究開発機構, 関西光量子科学研究所放射光科学研究センター, 併任 (30844823)
Project Period (FY)	2021-04-01 – 2024-03-31
Project Status	Completed (Fiscal Year 2023)
Budget Amount *help	¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000) Fiscal Year 2023: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000) Fiscal Year 2022: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000) Fiscal Year 2021: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Keywords	放射光X線 / 磁性体薄膜 / XMCD
Outline of Research at the Start	磁性体多層膜の磁性分布の深さ方向の直接観測による、薄膜中に発現する磁気構造の発現機構を解明するため、軟X線共鳴磁気反射法による深さ分解X線磁気円二色性・X線磁気線二色性分光法を新たに開発する。本研究により、多彩な磁気構造が発現している根本的要因である磁気的相互作用の層毎の情報が詳細に明らかにでき、磁性薄膜の複雑な磁気構造に関する新しい学理の構築ならびに実用磁気デバイスの開発に大きく貢献できる。
Outline of Final Research Achievements	Magnetic thin films/multilayer films with a complex structure in the depth direction exhibit a variety of magnetic phenomena due to interactions between layers. In order to elucidate the mechanism of the development of magnetic structures in thin films, we installed a measurement device using the reflectance XMCD method using XMCD in the soft X-ray region, and conducted experiments on test samples. The measurement setup is a two-axis reflectometer, equipped with a magnetic field application mechanism using a permanent magnet that moves independently, and can apply a magnetic field in the plane and perpendicular to the sample. Similar measurements were performed across the Co L absorption edge, and XAS/XMCD spectral information and structural information based on reflectance were obtained simultaneously.
Academic Significance and Societal Importance of the Research Achievements	磁性体の応用先として重要な記録媒体などにおいても多層膜構造を利用して有用な特性が実現されている。このような磁性体多層膜の磁性分布の深さ方向の直接観測による、薄膜中おける磁気構造の発現機構を解明することに寄与できる。