A5085730707- ZnO doping and properties
- Electronic and Structural Properties of Oxides
- Ferroelectric and Piezoelectric Materials
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Optical measurement and interference techniques
- Laser Design and Applications
- Advanced Chemical Physics Studies
- Particle accelerators and beam dynamics
- Semiconductor materials and devices
- Copper-based nanomaterials and applications
- Electron and X-Ray Spectroscopy Techniques
- Advanced Vision and Imaging
- Multiferroics and related materials
- Physics of Superconductivity and Magnetism
- Radiation Therapy and Dosimetry
- X-ray Spectroscopy and Fluorescence Analysis
- Mass Spectrometry Techniques and Applications
- Acoustic Wave Resonator Technologies
- Plasma Diagnostics and Applications
- Magnetic and transport properties of perovskites and related materials
- Spectroscopy and Laser Applications
- Laser-Matter Interactions and Applications
- Laser Material Processing Techniques
- Ga2O3 and related materials
Kumamoto University
2024
Kyushu University
2014-2023
The University of Tokyo
2007-2020
Japan Fine Ceramics Center
2008-2020
National Institute for Materials Science
2020
National Institute of Advanced Industrial Science and Technology
2020
National Defense Academy of Japan
2020
Engineering (Italy)
2020
Faculty (United Kingdom)
2020
Mitsubishi Electric (Japan)
1997-2019
Compressively strained SrTaO2N thin films were epitaxially grown on SrTiO3 substrates using nitrogen plasma-assisted pulsed laser deposition. Piezoresponse force microscopy measurements revealed small domains (101–102 nm) that exhibited classical ferroelectricity, a behaviour not previously observed in perovskite oxynitrides. The surrounding matrix region relaxor ferroelectric-like behaviour, with remanent polarisation invoked by domain poling. First-principles calculations suggested the and...
Techniques capable of localized imaging the structure hydrogen-bearing crystalline materials at atomic scale have been conspicuously absent. We show that annular bright field scanning transmission electron microscopy enables direct hydrogen columns within a sample vanadium dihydride, VH2. The suitability this technique for quantification content is discussed.
In order to find relationships among the atomic structure, electronic and defect energetics, $[001](310)\ensuremath{\Sigma}5$ grain boundaries (GBs) of ${\text{SrTiO}}_{3}$ ${\text{BaTiO}}_{3}$ were investigated by using first-principles calculations high-resolution scanning transmission electron microscopy. It was found that rigid-body translations one with respect other are indispensable obtain stable GB translation plays an important role reduce structural distortions such as dangling...
Water is composed of two strong electrochemically active agents, H+ and OH− ions, but has not been used as an electronic material in oxide semiconductors. In this study, we demonstrate that water-infiltrated nanoporous glass electrically switches semiconductor from insulator to metal. We fabricated a field-effect transistor structure on semiconductor, SrTiO3, using glass—amorphous 12CaO·7Al2O3—as the gate insulator. Positive voltage, electron accumulation, water electrolysis electrochemical...
Piezoelectric materials play a key role in applications, while there are physically open questions. The physical origin of piezoelectricity is understood as the sum contributions from intrinsic effects on lattice dynamics and those extrinsic ferroic-domain dynamics, but an incomplete understanding that all classified effects. Therefore, accurate classification important for piezoelectricity. In this work, high-energy synchrotron radiation X-ray diffraction utilized to measure response BiFeO3...
The role of Pr doping on double Schottky barrier formations at ZnO single grain boundaries was investigated by the combination current-voltage measurements, atomic-resolution Z-contrast scanning transmission electron microscopy, and first-principles calculations. Although segregated to specific atomic site along boundaries, it found not be direct cause nonlinear properties. Instead, under appropriate annealing conditions, enhances acceptor-type native defects that are essential for creation...
Various properties of ceramics can be significantly influenced by the presence grain boundaries. The influence on is closely related to grain‐boundary atomic structures. As different boundaries have structure, properties. It difficult examine structure and individual in ceramics. In order understand atomic–structure–property relationships, well‐defined single should characterized. present paper, we review our recent results investigations structures electrical ZnO relationships between were...
Abstract The absorption and cicular dichroism spectra of the complex poly‐ L ‐lysine (PLL) in random coil form with methyl orange (MO) have been measured aqueous solution. A new band is observed at shorter wavelength compared that free dye. Although MO does not show a formation dimer or aggregation an increase concentration, circular bands are corresponding to band. These induced may arise from dimeric molecules bound PLL form. main contribution interaction between shown be electro static...
The ultrahigh piezoelectricity of lead magnesium niobate-lead titanate (PMN-PT) single crystals is utilized for medical imaging and ultrasonic devices. It has been revealed that the domain structure miniaturized down to nanometer scale, indicating its response electric fields could play more roles. In this Letter, we report real-time direct observations polarization reversals in PMN-PT with use situ electrical biasing transmission electron microscopy. We find a dominant behavior reversible...
A method for the shape measurement of curved objects has been developed using multiple slit-ray projections and a turntable. The object is placed on computer-controlled turntable irradiated by two directed projectors. An ITV camera takes line image reflection from object, computer calculates space coordinates surface. By projections, total surface attained accurately.
Abstract A large piezoelectric response in ferroelectric ceramics is typically associated with extrinsic contributions from domain structures. However, such structures cannot be expected systems pseudo-cubic symmetry. In this study, we determine the mechanism of significant piezoelectricity and ferroelectricity 0.3BaTiO 3 –0.1Bi(Mg 1/2 Ti )O –0.6BiFeO ceramic a perovskite-type Synchrotron radiation X-ray diffraction reveals that Bi ions essentially prefer to off-centered at six sites by...
Introduction This cross-sectional study aimed to characterize the viable vaginal microbiota and identify host factors influencing this by employing a combination of relative quantitative analyses. Methods Twenty-four fluid samples were collected from healthy adult Japanese women for analysis. Vaginal pH was measured using portable meter. DNA extracted fluid, 16S ribosomal RNA gene sequences in V3-V4 regions analyzed bacterial species. Additionally, cultured on four types selective agar...
This paper focuses on simulating text dialogues in which impressions between speakers improve during speed dating. simulation involves selecting an utterance from multiple candidates generated by a generation model that replicates specific speaker's utterances, aiming to the impression of speaker. Accurately improves is crucial for simulation. We believe whether dialogue partner's speaker may depend personalities both parties. However, recent methods selection do not consider per or...
Attention mechanisms have played a crucial role in the success of Transformer models, as seen platforms like ChatGPT. However, since they compute attentions from relationships between only one or two object types, fail to effectively capture multi-object real-world scenarios, resulting low prediction accuracy. In fact, cannot calculate attention weights among diverse such `comments,' `replies,' and `subjects' that naturally constitute conversations on Reddit X, representing simultaneously...
We theoretically investigated the dynamics of structural deformations CO(2) and its cations in near-infrared intense laser fields (approximately 10(15) W cm(-2)) by using time-dependent adiabatic state approach. To obtain "field-following" potentials for nuclear dynamics, electronic Hamiltonian including interaction with instantaneous electric field is diagonalized multiconfiguration self-consistent-field molecular orbital method. In CO(2+) stages, ionization occurs before intensity becomes...
Ferroelectricity has recently been observed in wurtzite-structured Sc-doped AlN thin films, five years after our initial prediction of ferroelectricity wurtzite compounds based on first-principles calculations. The films exhibited a much higher coercive voltage (3 MV/cm) than that conventional perovskite-structured ferroelectric material PbTiO3, however, making it difficult to switch the films’ polarity and limiting their practical application. To identify tetrahedral materials with low...
The atomic structure of [0001]-tilt grain boundaries in ZnO was investigated using high-resolution transmission electron microscopy (HRTEM) and atomistic calculations. HRTEM observation conducted for [0001] fiber-textured thin films grown on quartz-glass substrates by the pulsed-laser deposition. observed can be classified into three types: low-angle composed irregular dislocation arrays, with ${10\overline{1}0}$ facet structures, near-low $\ensuremath{\Sigma}$ represented symmetric...
Very recently, Ohsawa et al. have presented a new experimental apparatus for measuring doubly differential cross sections of electron emission from water vapor with fast heavy-ion impact $(6--25\phantom{\rule{0.3em}{0ex}}\mathrm{MeV})$. Successful measured energy and angular distributions secondary electrons were produced collision $6.0\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕\mathrm{u}$ ${\mathrm{He}}^{2+}$ ions [Nucl. Instrum. Methods Phys. Res. B 227, 431 (2005)]...