Nanostructure Magnetism Laboratory (Material functional analysis & evaluation)
|Staff & Contact|
|Educational Staff||Associate Prof. Nobuyoshi Hosoito
Assistant Prof. Takanobu Jujo
Education and Research Activities in the Laboratory
In the Nanostructure Magnetism Laboratory, we use vacuum deposition and sputtering methods to produce metallic magnetic thin and multilayer films, and conduct basic research on magnetic phenomena specific to nanostructure thin films and the relationship between the structure of thin films and magnetism. The laboratory is characterized by research on “nanostructure magnetism” with synchrotron radiation X-rays. We are developing an X-ray magnetic scattering technique that enables element-specific magnetic structure analysis through the improvement of measuring methods, sensitivity enhancement and analysis precision.
Magnetic thin films and multilayer films with modulated structures at nanoscale can produce various magnetic structures and magnetization processes because of the effects of magnetic anisotropy in the individual magnetic layers, as well as the direct or indirect exchange coupling between the magnetic layers. Thus, we elucidate element-specific magnetic structures and vector magnetization processes by resonant X-ray magnetic scattering techniques, and reveal the generation mechanism of magnetic functionalities. In spin electronics, which is recently attracting attention, “magnetism in nonmagnetic layers” or “magnetism of conduction electrons” is related to the appearance of functionalities. The resonant X-ray magnetic scattering allows us to study the magnetism in nonmagnetic layers without being affected by the magnetism in ferromagnetic layers. We take advantage of these characteristics to advance our research on conduction electron magnetism.
In our laboratory, based on the specialized knowledge and experimental technology of solid state physics, especially of magnetism obtained from the above studies, we, for educational purposes, cultivate human resources with the ability to discover problems, explore solutions, discuss issues logically, give presentations on research results, and will demonstrate their ability in companies, universities, and research institutions after graduation.
1. Induced magnetic structures of nonmagnetic layers and their vector magnetization processes in the oscillatory interlayer exchange coupling systems such as Fe/Au and Co/Cu multilayers
2. Interface magnetism in the indirect exchange bias systems such as CoO/Cu/Fe and FeMn/Cu/Co trilayers
3. Induced magnetism of Pt layers in the Fe/Pt multilayers with perpendicular magnetic anisotropy
Fig. 1 Resonant X-ray magnetic scat¬tering profiles in (a) parallel and (c) antiparallel states of Fe magnetizations measured near the Au L3 absorption edge, and induced magnetic structures of Au layers in (b) parallel and (d) anti-parallel states of Fe magnetizations.
Recent Research Papers and Achievements
1. M. Lee, R. Takechi, and N. Hosoito, “Perpendicular Magnetic Anisotropy and Induced Magnetic Structures of Pt Layers in the Fe/Pt Multilayers Investigated by Resonant X-ray Magnetic Scattering”, J. Phys. Soc. Jpn. 86, 024706-1-10 (2017).
2. S. Amasaki, M. Tokunaga, K. Sano, K. Fukui, K. Kodama, and N. Hosoito, “Induced Spin Polarization in the Au Layers of Fe/Au Multilayer in an Antiparallel Alignment State of Fe Magnetizations by Resonant X-ray Magnetic Scattering at the Au L3 Absorption Edge”, J. Phys. Soc. Jpn. 84, 064704-1-8 (2015).