Nanostructure Magnetism Laboratory (Material functional analysis & evaluation)
|Staff & Contact|
|Educational Staff||Associate Prof. Nobuyoshi Hosoito|
Education and Research Activities in the Laboratory
In the Nanostructure Magnetism Laboratory, we use the vacuum deposition and sputtering methods to produce metallic magnetic thin films 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 on the nanoscale can produce various magnetic structures and magnetization processes because of the effects of the magnetic anisotropy in the individual magnetic layers, as well as 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 magnetism of conduction electrons.
In our laboratory, based on the specialized knowledge and experimental technology on solid state physics, especially on magnetism, obtained from the above study, we, for educational purposes, cultivate human resources who have the ability to discover problems, search for solutions, discuss issues logically, give presentations on research results, and demonstrate their ability in companies, universities, and research institutions after graduation.
1. The induced magnetic structure and magnetization process for the conduction electrons in nonmagnetic layers of the magnetic /nonmagnetic multilayer film that produces oscillatory interlayer exchange coupling or giant magnetoresistance effect
2. Vector magnetization process caused by direct and indirect exchange coupling and magnetic anisotropy
3. Mechanism of the exchange bias effect
Explanatory Pictures of Research Activities
- Fig.1 Magnetic field dependence of the magnetic structure induced in the Au layers of an Fe/Au multilayer film
- Fig.2 Magnetic scattering profile generated by uncompensated magnetization induced in the antiferromagnetic MnIr layer of an exchange bias film (Ir L3 absorption edge)
Recent Research Papers and Achievements
1.”Au Spin Polarization Induced in an Fe/Au(001) Multilayer with Interlayer Exchange Coupling from the X-ray Energy Dependence of Resonant X-ray Magnetic Scattering at the Au L3 Absorption Edge” N. Hosoito, K. Kodama, R. Yamagishi, J. Phys. Soc. Jpn. 81 (2012) 064713-1-5