A5107637985- Semiconductor materials and devices
- Electronic and Structural Properties of Oxides
- Catalytic Processes in Materials Science
- Magnetic Properties and Synthesis of Ferrites
- Semiconductor materials and interfaces
- Integrated Circuits and Semiconductor Failure Analysis
- Surface and Thin Film Phenomena
- Silicon Carbide Semiconductor Technologies
- Copper Interconnects and Reliability
- Silicon and Solar Cell Technologies
- Advanced Chemical Physics Studies
- Iron oxide chemistry and applications
- Theoretical and Computational Physics
- Force Microscopy Techniques and Applications
- Gas Sensing Nanomaterials and Sensors
- Multiferroics and related materials
- Quantum, superfluid, helium dynamics
- Molecular Spectroscopy and Structure
- TiO2 Photocatalysis and Solar Cells
- Cardiac Arrhythmias and Treatments
- Pharmacy and Medical Practices
- Spectroscopy and Quantum Chemical Studies
- Sports injuries and prevention
- Nonlinear Optical Materials Research
- Cold Atom Physics and Bose-Einstein Condensates
Shiga University of Medical Science
2025
The University of Tokyo
1979-2024
Ricoh (Japan)
2018
Tokyo University of Science
1981-2017
Toshiba (Japan)
1993-2013
Japan Science and Technology Agency
2013
Hitachi (Japan)
2001
Significance Surfaces are gates to control the transport of energy and materials between gas phase bulk. For hydrogen storage, across surface is recognized as bottleneck, e.g., 1 H 2 in 1,000 impinging a Pd penetrates surface. Here, we demonstrate that alloying Pd(110) with submonolayer amounts Au dramatically accelerates absorption, by factor more than 40. This discovery will lead enhancement absorption kinetics, thereby improving performance hydrogen-purifying membranes hydrogen-storage...
Chemisorption of an ${\mathrm{O}}_{2}$ molecule from the topmost layer to deeper subsurface layers on Si(100) surface is studied by employing spin-polarized generalized-gradient approximation. The calculated results reveal that weakly adsorbed a clean with initial spin-triplet state, but adiabatically chemisorbed spin-state conversion, when arrives at low incident energy. Barrierless back-bond oxidation has been found occur through dissociative chemisorption spin-orbit interaction followed...
The existence of ferroelectricity in magnetite has been established by determining the c -axis component spontaneous polarization at 4.2 K. ferroelectric D - E hysteresis loop was observed changing applied electric field stepwise 5 kV/cm intervals 10 s between -15 and 15 kV/cm. It found that, K, coercive is extremely high leakage current still prominent. switching process d 20
Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiac disorder characterized by progressive fibrofatty replacement of the myocardium. In Japanese population, variants desmoglein-2 (DSG2) gene are a major cause ACM, typically following autosomal recessive inheritance pattern. Myosin-binding protein C (MYBPC3) primarily associated with hypertrophic (HCM). Here, we report severe pediatric case ACM compound heterozygous DSG2 and MYBPC3 variants. A 6-year-old asymptomatic girl was diagnosed...
We have found a series of resonances associated with the bound state (polyexcitons, PE(N)s) N excitons up to N=6 in emission spectra diamond under two-photon excitation at around 10 K. Time-resolved show stepwise formation PE(N)s smaller larger N, as well successive decay from N. At higher levels, transformation into condensed phase electron-hole droplets occurs. The binding energies PE(N)s, normalized exciton Rydberg energy, agree those silicon, suggesting universality phenomena.
Silicon carbide (SiC)-based metal–oxide–semiconductor devices suffer from carrier mobility degradation due to defects at the SiC/SiO2 interface. The carbon-related Si2>C=O and Si2>C=C<Si2 are thought be possible origins of defect levels. We studied electronic structures 4H-SiC(0001)/SiO2 interfaces with C=O C=C by first-principles calculations based on hybrid density functional theory. found that their levels strongly affected local around groups, form a broad state distribution.
We investigate ultrahigh concentration doping of hydrogen (H) into rutile-TiO
Magnetoelectric effects of magnetite at 4.2 K were measured by applying magnetic field with both dc and ac methods. Analyses the signals indicate that crystal symmetry is nearly monoclinic but exactly triclinic. The results measurements different magnitude applied suggest electric poralization induced mainly rotation magnetization. polarization along b -axis, however, can not be explained this mechanism only.
After introducing briefly the derived electronic superstructure of Fe304, recent advances in model are explained. The transition may be described as ordered microsegregation linked molecular pseudo-metallic units. Mössbauer results predicted that population ratio Fe2+−II to Fe2+−I is 3:5 contrast 4:4 previous understanding and all consistently understood by assuming Fe2+ ions have a Jahn-Teller stabilized dεξη orbital for additional electron. We observed ferroelectric hysteresis curves at...
The dissociative adsorption of water, migration hydrogen, and molecular hydrogen generation on anatase rutile TiO2 surfaces were studied by first-principles calculations. Whereas dissociated H OH are adsorbed strongly both surfaces, the energies substantially decreased when combined with polarons, which can be generated through photoexcitation. atom coupled a polaron was found to undergo codiffusion. While large smoothly follows in anatase, small stochastically moves abruptly jumps between...
Thermally produced SiC/SiO2 stacking in SiC MOSFETs creates defect-related interfacial states and around the band gap of SiC. These can cause serious reliability problems such as threshold voltage shift, well efficiency channel mobility degradation. Carbon species having C=C double bonds have been suggested one origins these states. We theoretically shown that this type defect produces SiC, they be removed by saturating bond reactions with H2 F2. The single-bond products are found to stable...
Abstract The origin of the scanning tunneling microscopy (STM) zigzag chain structures composed pairs pentagons on Si(110)-(16 × 2) surface is unveiled through first-principles calculation method. Stable Si(110) structures, both flat and stepped surfaces, have been discovered. energy gain stable step structure larger than those previously proposed models by 5.0 eV/(16 cell or more. consists buckled tetramers, heptagonal rings, tetragonal threefold-coordinated Si atoms, but no pentagonal...
The atomic and electronic structure of ${\mathrm{SrTiO}}_{3}$(001) surfaces is investigated by low-energy electron diffraction, Auger spectroscopy, force microscopy, ultraviolet photoemission spectroscopy (UPS), theoretical calculations. While the surface ${\mathrm{TiO}}_{2}$-terminated after annealing at $1225{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\mathrm{C}$ for 72 h, an SrO-terminated realized along with a...
Hydrogen is involved in various important chemical processes on metal-oxide surfaces. Due to its electron-donating character, hydrogen tends form polaronic states, where the electron spatially separated from proton, which exerts significant impact electronic properties of By individually probing proton with nuclear reaction analysis and ultraviolet photoelectron spectroscopy combination density functional theory calculations, we clarify state anatase ${\mathrm{TiO}}_{2}(101)$ surface. found...
Several of our experimental results, as seen from the side symmetry breakdown this most characteristic material, will be shown. X-ray study reveals that lattice constant decreases approximately by 7×10−6 per degree room temperature to Verwey Tv. At Tv, cell volume increases about 6×10−4, suggesting presence covalent nature in crystal. crystal transforms monoclinic. Although there is a report another transition at 12°K, very careful work and NMR showed no discontinuous change region accuracy...
While the a- and m-faces of 4H-SiC have attracted increasing interest for SiC metal–oxide–semiconductor device applications, electronic and/or geometric structures their SiC/SiO2 interfaces are still unknown. We constructed model defect-free abrupt interfaces. Even with C–O bonds at interface an uneven interfacial boundary, properties show only slight difference from those Si-face a flat no-interface bonds. Our results offer starting point studying whether smaller number defects compared is...
Silicon self-interstitial migration paths and barrier energies have been investigated based on a first-principles critical-path calculation for atomic motions. Self-interstitials are moved through critical corresponding to the lowest-energy configurations thermal diffusion. The results suggest that diffusion occurs mainly as combination of interstitial-interchange direct-interstitial mechanisms begins from stable hexagonal tetrahedral configurations. interstitialcy-interchange mechanism has...
The Nuclear Reaction Analysis (NRA) system was successfully improved in terms of the control dynamic hydrogen migration and reducing background noise. proposed new achieved nondestructive measurements depth profile with a detection limit less than 3×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">19</sup> atom/cm xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . Secondary Ion Mass Spectrometry (SIMS) NRA this were compared analysis gate...
The oxidation reaction of an unpaired dangling bond (DB) and a DB atomic wire on hydrogen-terminated Si(100) 2×1 surface was studied using ultrahigh-vacuum scanning tunneling microscopy. We found that O2 molecules dissociated into oxygen after reacting with DBs. oxidized also the bonds near turned to be considerably enhanced at wire, compared DB. This suggests electron transfer anti-bonding π orbital molecule depends local density states wire.
Since a new method has developed on partial discharge (PD) detection from insulation joints (IJs) in long-distance XLPE cable lines, the PD measuring tests using this technique have come into common use for confirming soundness of lines. This we call S. P. O. M enables us not only to detect safely and easily but also calibrate sensitivity indirect calibration metallic-foil electrodes attached both insulated surfaces an IJ. Although PDs normal joint (NJ) cannot be detected at NJ, attenuated...
Theoretical analyses predict that large Schottky barrier reduction by sulfur doping at NiSi/Si junction is induced S2 formation. The formation may have occurred in silicidation process, even under low temperature rapid thermal annealing. We demonstrated implanted into silicon forms configuration annealing, based on first principles calculations and kinetic Monte Carlo (KMC) simulations.