A5051591022- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- ZnO doping and properties
- Multiferroics and related materials
- Semiconductor materials and devices
- Magnetic Properties and Synthesis of Ferrites
- Semiconductor Quantum Structures and Devices
- Electron and X-Ray Spectroscopy Techniques
- Organic Light-Emitting Diodes Research
- Advanced Electrical Measurement Techniques
- Molecular Junctions and Nanostructures
- High voltage insulation and dielectric phenomena
- Perovskite Materials and Applications
- Electrochemical Analysis and Applications
- Non-Destructive Testing Techniques
- Advanced Research in Systems and Signal Processing
- Chalcogenide Semiconductor Thin Films
- Analytical Chemistry and Sensors
- Gyrotron and Vacuum Electronics Research
- Sensor Technology and Measurement Systems
- Quantum and electron transport phenomena
- Terahertz technology and applications
- Heusler alloys: electronic and magnetic properties
- Electronic and Structural Properties of Oxides
The University of Tokyo
2021-2025
Toyota Motor Corporation (Japan)
2024
Substituting rare-earth Eu ions with a large atomic number into 3d transition metal oxides can precisely control their magnetic properties through significant spin-orbit coupling, leading to noncollinear magnetism. Experimental investigations are combined density functional theory explore site-selective Eu3+ substitution as strategy enhance the of Fe3O4 thin films. The location Eu3+, that is, octahedral versus tetrahedral, is confirmed by electrical resistivities and valence band...
We investigated the Ru $4d$ and O $2p$ electronic structure magnetic properties of an ultrahigh-quality $\mathrm{SrRu}{\mathrm{O}}_{3}$ film on $\mathrm{SrTi}{\mathrm{O}}_{3}$ grown by machine-learning assisted molecular-beam epitaxy. The high itinerancy long quantum lifetimes quasiparticles in ${t}_{2g}$-O hybridized valence band are confirmed observing prominent well-screened peak $3d$ core-level photoemission spectrum, coherent near Fermi energy valence-band oscillations resistivity....
Epitaxially strained ${\mathrm{SrRuO}}_{3}$ films have been a model system for understanding the magnetic anisotropy in metallic oxides. In this paper, we investigate of Ru $4d$ and O $2p$ electronic structure properties using high-quality epitaxially (compressive tensile) grown by machine-learning-assisted molecular beam epitaxy. The element-specific hybridization between orbitals were characterized ${M}_{2,3}$-edge $K$-edge soft x-ray absorption spectroscopy circular dichroism...
The stable performance of organic photodiodes (OPDs) is crucial for realizing reliable photosensing and their facile integration into larger systems. However, OPDs with the commonly used ZnO electron transport layer (ETL) suffer from photoinstability, where dark current increases by several orders magnitude after light irradiation, thereby affecting stability photodetection. Herein, increase in irradiation ETL suppressed to approximately twice its initial value. This suppression achieved...
Since charge injection from metals into insulating polymers leads to electrical degradation and failure of various devices, it is essential clarify the band alignment at metal/insulating polymer interface. However, electronic structure interface has not been studied experimentally. In this contribution, alignments Au/polytetrafluoroethylene (PTFE) Au/polypropylene (PP) interfaces were determined by first-principles calculations using density functional theory (DFT) X-ray photoelectron...
Strong spin-charge interactions in several ferromagnets are expected to lead subpicosecond (sub-ps) magnetization of the magnetic materials through control carrier characteristics via electrical means, which is essential for ultrafast spin-based electronic devices. Thus far, has been realized by optically pumping a large number carriers into d or f orbitals ferromagnet; however, it extremely challenging implement gating. This work demonstrates new method sub-ps manipulation called...
Fe-doped III-V ferromagnetic semiconductor (FMS) (In,Fe)Sb is a promising material for spintronic device applications because of the n-type carrier conduction and ferromagnetism with high Curie temperature (TC > 300 K). To clarify mechanism high-TC ferromagnetism, we have investigated electronic structure magnetic properties an thin film by performing x-ray absorption spectroscopy (XAS) circular dichroism (XMCD) measurements at Fe L2,3 edges. The magnetic-field dependence XMCD spectra...
We investigated the Ru 4d and O 2p electronic structure magnetic properties of an ultra-high-quality SrRuO3 film on SrTiO3 grown by machine-learning-assisted molecular beam epitaxy. The high itinerancy long quantum lifetimes quasiparticles in t2g-O hybridized valence band are confirmed observing prominent well-screened peak 3d core-level photoemission spectrum, coherent near Fermi energy oscillations resistivity. element-specific hybridization between orbitals were characterized M2,3-edge...
Inter-valence charge transfer (IVCT) is electron between two metal $M$ sites differing in oxidation states through a bridging ligand: $M^{n+1} + M'^{m} \rightarrow M^{n} M'^{m+1}$. It considered that IVCT related to the hopping probability of (or mobility) solids. Since controlling conductivity ferromagnetic semiconductors (FMSs) key subject for development spintronic device applications, manipulation may become new approach band engineering FMSs. In Ru-doped cobalt ferrite CoFe$_2$O$_4$...
${\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}$ (MnGa) with the $L{1}_{0}$ structure is a ferromagnetic material strong perpendicular magnetocrystalline anisotropy. Although MnGa thin films have been successfully grown epitaxially and studied for various spintronics devices, fundamental understandings of its electronic are still lacking. To address this issue, we investigated $L{1}_{0}$-MnGa using angle-resolved photoemission spectroscopy (ARPES). We observed large Fermi surface rhombic...
Since charge injection from metal into dielectric leads to electrical degradation and failure of various power devices, it is essential reveal the band alignment metal/dielectric interface. However, interface remains theoretically unexplored has not been experimentally obtained. This paper reveals at Au/polypropylene (PP) by X-ray photoemission spectroscopy (XPS) measurements. The hole barrier Au/PP was measured be 3.4 eV.
Since charge injection from metal into dielectrics leads to electrical degradation and failure of various power devices, it is essential reveal the band alignment metal/dielectric interface. However, interface remains theoretically unexplored has not been experimentally obtained. This study reveals at Pt/polytetrafluoroethylene (PTFE) by X-ray photoelectron spectroscopy (XPS) measurements first-principles calculations using density functional theory (DFT). Experiments that electron hole...
Ferromagnetic Semiconductors In article number 2301347, Le Duc Anh, Iwao Matsuda, Masaaki Tanaka, and co-workers demonstrate the first sub-picosecond (≈600 fs) magnetization process in a ferromagnetic quantum well, which utilizes high carrier coherency rapid photo-Demba field effect, using pump-and-probe measurements with an X-ray free-electron laser. This could open new way to ultrafast magnetic storage information.