A5008895561- Ferroelectric and Piezoelectric Materials
- Acoustic Wave Resonator Technologies
- Microwave Dielectric Ceramics Synthesis
- Multiferroics and related materials
- Dielectric materials and actuators
- Liquid Crystal Research Advancements
- Electronic and Structural Properties of Oxides
- Particle physics theoretical and experimental studies
- Physics of Superconductivity and Magnetism
- Nuclear Physics and Applications
- Radiation Detection and Scintillator Technologies
- Semiconductor Lasers and Optical Devices
- Advanced Sensor and Energy Harvesting Materials
- Anesthesia and Pain Management
- Innovative Energy Harvesting Technologies
- High-Energy Particle Collisions Research
- Semiconductor materials and devices
- Quantum Chromodynamics and Particle Interactions
- Ultrasonics and Acoustic Wave Propagation
- Quantum, superfluid, helium dynamics
- Energy Harvesting in Wireless Networks
- Atomic and Subatomic Physics Research
- Thin-Film Transistor Technologies
- Dielectric properties of ceramics
- Advanced Optical Imaging Technologies
Shonan Institute of Technology
2016-2025
Tokyo University of Science
1991-2023
Kumamoto University
2023
Tokyo Institute of Technology
2023
Takeda (United States)
2023
Mitsubishi Electric (Japan)
2018
Aoyama Gakuin University
2006
Merck (Japan)
1998-2004
NEC (Japan)
1989-2003
Toshiba (Japan)
1995-2002
Neodymium-doped Bi4Ti3O12 (BNT) films are evaluated for use as lead-free thin-film piezoelectrics in microelectromechanical systems. Bi4Ti3O12, Bi3.25La0.75Ti3O12, and Bi3.25Nd0.75Ti3O12 were fabricated by chemical solution deposition on Pt/TiOx/SiO2/Si substrates. Nd substitution promoted random orientation with low (00l) diffraction peaks. The 1-μm-thick film annealed at 750 °C exhibited a remanent polarization of 26 μC/cm2. Typical butterfly field-induced strain loops obtained the BNT...
Ferroelectric BaTiO 3 thin films were prepared on Pt(111)/ SiO 2 /Si(100) substrates at 650° C by the sol-gel method. Film thickness could be varied repeating a dip coating/heating cycle. The texture of became more dense and homogeneous when film increased. crystalline showed microstructure with grains as small 20–30 nm. dielectric properties measured for thicker than 0.25 µ m. With increasing thickness, constant remanent polarization increased coercive field decreased. Loss tangent was...
Lead-free piezoelectric K0.5Na0.5NbO3 thin films for microelectromechanical systems were fabricated via chemical solution process using metal alkoxide. Perovskite (KNN) single-phase with good leakage current properties successfully prepared by optimizing the KxNaxNbO3 (x≧0.5) composition of precursor solution. The KNN from K0.55Na0.55NbO3 showed typical ferroelectric P–E hysteresis and field-induced strain loops. 2Pr 2Ec values 14 µC/cm2 140 kV/cm, respectively. From slope butterfly loop,...
A direct search has been made for supermassive relics (heavier than about ${10}^{12}$ GeV/${\mathit{c}}^{2}$) with a 2000-${\mathrm{m}}^{2}$ array of CR-39 track-etch detectors deployed underground 2.1 yr. The nonobservation penetrating tracks places new upper limit the velocity-dependent flux at 3.2\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$...
Abstract We investigated the effectiveness of poling processes for Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO single crystals (SCs) produced using a continuous feeding Bridgman method, which is known to produce high property uniformity. The four studied are: (I) standard direct current (STD-DCP); (II) low-voltage field-cooling DCP (LV-FCP); (III) high-voltage (HV-FCP); and (IV) mid-temperature alternating (MT-ACP). highest free dielectric constant ( ε 33 T / 0 ) piezoelectric d were obtained by MT-ACP =...
Sublattice reversal epitaxy is demonstrated in lattice-matched GaAs/Ge/GaAs (100) and (111) systems using molecular beam epitaxy, confirmed by reflection high energy electron diffraction preferential etching. In the system, sublattice assisted self-annihilation of antiphase domains generated at GaAs/Ge interface. results from unique structure As-terminated Ge surfaces. The quality sublattice-reversed GaAs crystal investigated cross-sectional transmission microscopy. A method to fabricate a...
Ru and RuO 2 thin films were prepared by RF magnetron sputtering. The crystalline structure electrical properties of these investigated. Reactive sputtering a ruthenium metal target was carried out in mixed gas argon oxygen at 580° C. Total pressure ( P O + Ar ) controlled to maintain constant 1 Pa. single phase could be obtained when 0.5 Pa the deposition rate about 30 nm/min. resistivity 290 nm-thick deposited on SiO (1000 nm)/Si 54.9 µ Ω· cm. However, increased with decreasing film...
We present evidence for the non-Abelian nature of QCD from a study multijet events produced in ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilations \ensuremath{\surd}s =50 to 57 GeV AMY detector at KEK storage ring TRISTAN. A comparison three-jet event fraction TRISTAN DESY PETRA shows that coupling strength ${\ensuremath{\alpha}}_{s}$ decreases with increasing ${Q}^{2}$. In addition, measurements angular distributions four-jet show triple-gluon vertex.
Abstract An exceptionally large free dielectric permittivity of 14200, piezoelectric coefficient ( d 33 ) 4800 pC/N and calculated electromechanical coupling factor k 95.7% were obtained from Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) - Pb(Zr,Ti)O (PZT) single crystals (SCs) under AC poling (ACP). The PMN −0.3PZT SCs grown by a solid-state crystal growth (SSCG) method with high composition uniformity showed phase change temperature 57 °C–72 °C Curie T c 140 °C. measured 250 was after heat treatment at °C,...
Ferroelectric BaTiO 3 thin films have been successfully prepared by sol-gel process using barium and titanium isopropoxides as precursor solutions for dip-coating. Homogeneous obtained on various substrates preheating gel at 120°C in a flow of oxygen/water vapor mixed gas, successive heating 650°C oxygen atmosphere. The introduction water during is very effective the crystallization relatively low temperatures. These exhibit good crystallinity smooth surfaces with grains small about 50 nm....
Ba(ZrxTi1-x)O3 (BZT; x = 0.1 and 0.2) ceramics are prepared by spark plasma sintering (SPS) conventional sintering. By normal sintering, the density, grain size, dielectric constant of increase with temperature. The temperature dependence is enhanced sharp anomaly in sintered at high application SPS, more than 96% relative densities could be obtained 1100 °C for 5 min air atmosphere. Grain growth suppressed SPS. average size was less 1 µm. BZT SPS subsequent annealing 1000 12 h exhibit a...
Imaging of the phase and magnitude piezoelectric strain in Pb(Zr0.3, Ti0.7)O3 (PZT) capacitors is performed with an atomic force microscope. The imaging reveals a significant spatial dependence ferroelectric properties both fatigued unfatigued PZT films. We propose that variation related to domain structure PZT. Through measurement local hysteresis loops strain, areas are observed exhibit shifted along polarization axis. In some regions samples, such remanent points curve have same...
The anomalous dielectric absorption current of BaTiO 3 ceramics when an electric field is applied at above the Curie point was measured. results cannot be explained by famous Maxwell-Wagner double layer theory. total charge charging and discharging more than 1000 µC/cm 2 . giant space produces “internal bias field” in opposite direction to first field. Another generated during aging process after poling below point. In this report, two types effects are described discussed respect “space...
BaTiO3 (BT) ceramics are prepared by spark plasma sintering (SPS) and conventional sintering. In sintering, the density grain size of increase with temperature. SPS, more than 97% relative densities can be obtained at 900 °C for 5 min in air atmosphere. Compared SPS suppresses growth ceramics. The average BT subsequent annealing 1000 12 h is less 1 µm. exhibit a high dielectric constant 6020. field-induced displacement larger that sintered conventionally. dynamic strain/field 15 kV/cm was 540 pm/V.
BaTiO3 (BT) ceramics with various grain sizes are prepared by spark plasma sintering (SPS), two-step sintering, and conventional sintering. The field-induced displacement piezoelectric constant measured a resonant–antiresonant frequency method evaluated. BT SPS characterized high permittivity, loss tangent, linear-field-induced strain, low Qm, exhibit relatively higher strain d31 value than the fine-grained fabricated other methods. These characteristics of SPS-BT probably due to internal...
The preparation of reduction-resistant (Ba,Ca)TiO 3 ceramics as lead-free piezoelectric materials was studied. To improve their electrical properties, (100),(001)-oriented (Ba 0.85 Ca 0.15 )TiO were fabricated by the reactive templated grain growth method using a mixture platelike CaTiO and BaTiO particles. particles prepared through topochemical microcrystal conversion process CaBi 4 Ti O 15 BaBi plate-like precursor crystals. 100 orientation degree grain-oriented 92%, estimated Lotgering's...
It is said that water we use in daily life insists on several molecules connected with hydrogen bonding.However, the quantum dynamics of after hydrogen-bond dissociation has not been researched so far, although there are many a study relating to bonding its other chemical compounds.We focus bond-dissociated supposed possess elementary particle-like matter high pressure approximately 100 MPa water.The described as <H + ~e->, which proton and electron exist neither separately nor forming...
The temperature dependence of the electrical and electromechanical properties Pb(Zr,Ti)O3 (PZT) (Zr/Ti=30/70, 52/48, 70/30) thin films are investigated. 1-μm-thick PZT were prepared on (111)Pt/Ti/SiO2/Si substrates by chemical solution deposition. dielectric ferroelectric measured in range from −250 to 150 °C. temperature-dependent strain loops using scanning probe microscopy −100 field-induced displacement increased with increase temperature; however, their was relatively small, compared...
The total cross section for e+e− annihilation into hadrons has been measured CM energies ranging from 50 to 57 GeV. We fit the predictions of standard model these measurements and those at lower energies. mass Z0 boson, MZ, QCD scale parameter, ΛMS, are derived fit. results MZ=88.6−1.8+2.0 GeV/c2, ΛMS=0.15−0.11+0.16